The routines of the PHonon package can be divided in groups of related task. There are high level drivers that call the routines that do the actual work and low level routines that make a single task. Note that the phonon code is tightly integrated in the QE package, so it uses the routines provided by the Modules or by the PW/src directories. Only a brief comment on the purpose and the use of the routines can be found here. More details might be written inside the routines themselves. We report here the name of the file that contains the routines. Each file might contain more than one routine. Unfortunately sometimes there is no correspondence between the name of the file and the name of the routine. This is mainly for historical reasons. We adopt the following convention: if the file and the routine contained inside have the same name we report only the filename; if the file contains a single routine with a different name or more than one routine, we report in parenthesis the routine name.
Modules that contain the variables used by ph.x:
phcom.f90 Almost all global variables are here. elph.f90 Variables needed for the electron-phonon part. ramanm.f90 Variables for Raman calculation.
Global variables allocation and deallocation. Note that some variables are allocated by phq_readin and by ph_restart.
allocate_phq.f90 This is the main allocation routine in which almost all global variables are allocated. It needs only the dimensions defined in pw.x. allocate_part.f90 Allocate quantities for the partial computation of the dynamical matrix. It is called in phq_readin. allocate_pert.f90 Allocate the symmetry matrices in the basis of the modes. It needs the maximun number of perturbations. deallocate_part.f90 Deallocate the variables allocated by allocate part. deallocate_phq.f90 Deallocate all the ph.x variables allocated in allocate_phq. The variables allocated in phq_readin or ph_restart should be deallocated by destroy_status_run, contained in ph_restart. clean_pw_ph.f90 Clean all variables of pw.x and of ph.x. Used to reinitialize the calculation at each q.
Starting point and main programs. The directory PHonon/PH contains five executables whose main programs are:
phonon.f90 This is the main program of ph.x q2r.f90 This is the main program of q2r.x matdyn.f90 This is the main program of matdyn.x dynmat.f90 This is the main program of dynmat.x fqha.f90 This is the main program for fqha.x
Reading input, pseudopotentials, and files written by pw.x:
phq_readin.f90 This is the routine that reads the input, the PP and the punch file of pw.x. bcast_ph_input.f90 This routine broadcasts the input variables to all processors. save_ph_input.f90 (save_ph_input_variables) A few input variables are changed by the ph.x code and are saved by this routine. (restore_ph_input_variables) this routine restores the saved variables. (clean_input_variables) deallocate the saved variables.
Check the initial status of the calculation and decide what has to be computed:
check_initial_status.f90 Tests the initial status of the calculation, prepare or reads the mesh of q points and the irreps, divide the work among images and creates the necessary directories in outdir. (image_q_irr) Divide the work among several images. (collect_grid_files) Copy the files produced by images in the .phsave directory of the image0. check_if_partial_dyn.f90 Control partial calculations in phonon. check_restart_recover.f90 Check if a restart or recover file is present in the outdir directory
Routines that select the small group of q and other symmetry related quantities used by the ph.x code:
set_small_group_of_q.f90 This is a driver that selects among the s matrices those of the small group of q. Check if q-> -q+G symmetry exists. If modenum > 0 removes also the symmetries that do not send the mode in itself. (smallg_q) do the actual work of selecting the s matrices. mode_group.f90 Find the small group of q and of the mode (used with modenum) smallgq.f90 (set_giq) Find the G vectors associated to each rotation: Sq=q+G. sgam_ph.f90 Finds the rtau vectors. These are Bravais lattice vectors that link an atom na to its rotated atom nb if these two atoms are not in the same cell. These quantities are needed to rotate the modes and to symmetrize the potentials.
Routines that manipulate or generate the irreducible representations, the q-point mesh and all the preparatory stuff that is needed by the ph.x code:
q_points.f90 Generate the mesh of q vectors. check_q_points_sym.f90 Check if the q point mesh is compatible with the fft mesh used by q2r.x. init_representations.f90 This is a driver that initialize all the irreps for all q vectors. First it finds the small group of q and then calls find_irrep for each q. (initialize_grid_variables) This routine reads the irreps from file and sets the variables that define the grid of q and irreps. find_irrep.f90 Find the irreps of a given q calling set_irr or set_irr_nosym. (find_irrep_sym) is a driver that allocate the symmetry matrices in the basis of the modes and calls set_irr_sym to calculate them. random_matrix.f90 Generate the random matrix to calculate the irreps. set_irr.f90 Call random_matrix to generate a random matrix and symmetrize it. The eigenvectors are the irreps. Count their degeneracy and if search_sym is true find their symmetry. set_irr_nosym.f90 As set_irr in the case in which the system has no symmetry or symmetry is not used. set_irr_sym.f90 Calculate the rotation matrices on the irreps basis.
High level drivers that make the actual calculation:
prepare_q.f90 Decides if a given q has to be calculated and if it needs the band calculation or just to open the k-point list. initialize_ph.f90 Initialization driver. It calls the other initialization routines one after the other: allocate_phq, phq_setup, phq_recover, phq_summary, openfilq, and phq_init. phq_setup.f90 Setup many quantities needed by the phonon. The most significant are: the local+SCF potential, derivatives of xc potential, using dmxc or similar functions and setup_dgc, alpha_pv and occupated bands, rotation matrices on the basis of the mode (calling find_irrep_sym), setup the gamma_gamma tricks. phq_init.f90 Setup more complex quantities that require the implementation of more complex formula. It is a driver that uses auxiliary routines: set_drhoc, setlocq, dvanqq, drho, dynmat0. Moreover it computes becp1, alphap, eprec. phescf.f90 This is the main driver for the electric field perturbations. It decides what to compute on the basis of the input flags. It can compute polarization, epsilon, raman, and elop. phqscf.f90 This is the main driver for the phonon perturbation. It has a loop over the irreps at a given q. It calls solve_linter to calculate the perturbed wavefunctions and potentials, drhodv to update the dynamical matrix and add_zstar_ue to update the zue effective charges.
Opening and closing files:
openfilq.f90 Open almost all files of the ph.x code. close_phq.f90 Close the above files if opened.
Drivers that compute the band structure using the pw.x routines:
run_nscf.f90 This routine runs pw.x to calculate the bands. It calls init_run, electrons, and punch. However the functionalities of setup are provided by setup_nscf. set_defaults_pw.f90 (setup_nscf) This routine sets the input of pw.x with default values. It sets the k point list.
Routines that compute quantities independent from the perturbed wavefunctions that are used in the rest of the code (mainly US/PAW part). These routines are called by phq_init:
dvanqq.f90 This routine computes four of the five integrals of the augmentation functions and its derivatives with derivatives of the local potential. Needed only in the US/PAW case. drho.f90 This is a driver that computes the parts of the induced charge density and of the dynamical matrix that do not depend on the change of the wavefunctions. These terms are present only in the US/PAW case. It calls many of the following routines. compute_becsum_ph.f90 This routine computes becsum. compute_alphasum.f90 This routine computes alphasum. compute_becalp.f90 Compute the product of vkb and psi_{k+q} or of the derivative of vkb and psi_{k+q} compute_drhous.f90 This is a driver that makes a loop over the k points to accumulate, using incdrhous, the part of the induced charge density due to the change of the orthogonality constraint. All the modes are computed here. (US/PAW case only). compute_drhous_nc.f90 As compute_drhous in the noncollinear/so case. incdrhous.f90 Accumulate for a given k point and a given mode the contribution to the induced charge density due to the change of the orthogonality constraint. incdrhous_nc.f90 As incdrhous in the noncollinear/so case. compute_nldyn.f90 Computes the orthogonality term in the dynamical matrix. Used only in the US/PAW case. compute_weight.f90 Compute the composite weights for metals. qdipol_cryst.f90 This routine computes the dipole moment of the augmentation functions. setlocq.f90 This routine computes the local potential at q+G. compute_dvloc.f90 Computes the change of the local potential due to a phonon perturbation. setqmod.f90 Computes (q+G)**2 hdiag.f90 Computes the kinetic energy.
Lower level drivers that set up and solve the linear system to calculate the response of the system to a perturbation:
solve_linter.f90 Driver to calculate the phonon perturbation. solve_e.f90 Driver to calculate the static electric field perturbation. solve_e_fpol.f90 Driver to calculate the electric field perturbation at imaginary frequency. solve_e2.f90 Driver for the electric field perturbation at second order. solve_e_nscf.f90 A simplified version of solve_e in which the induced self consistent potential is already known. This routine is used in dhdrhopsi.f90.
Routines used by the above drivers to do their job. Some of these routines are used by all drivers, others are specific for a given perturbation:
dvpsi_e.f90 Compute the right hand side of the linear system in the electric field case (only non SCF part). It uses commutator_Hx_psi. commutator_Hx_psi.f90 Compute the commutator of the Hamiltonian with r. dvpsi_e2.f90 Compute the right hand side of the linear system for the second order perturbation in the electric field case. dvqpsi_us.f90 Compute the right-hand side of the linear system in the phonon case (Only non SCF part). It uses dvqpsi_us_only. dvqpsi_us_only.f90 The part of dvqpsi due to the nonlocal potential. cft_wave.f90 Wavefunction from real to reciprocal space and return. apply_dpot.f90 Add the contribution of the change of the SCF potential to the right-hand side of the linear system. adddvscf.f90 Add the additional US/PAW contributions to the right-hand side of the linear system (phonon case). adddvepsi_us.f90 As adddvscf for the electric field case. orthogonalize.f90 Apply the projector on the valence bands to the right-hand side of the linear system. Deal with both insulators and metals. cgsolve_all.f90 Solve the linear system with an iterative conjugate gradient method. pcgreen.f90 Orthogonalize and solve the linear system. Used by solve_e2 and solve_e_nscf instead of the more standard method. Call cgsolve_all for doing the actual calculation. gmressolve_all.f90 Solve the linear system in the case of imaginary frequency polarizability calculation. ch_psi_all.f90 Apply H+Q-eS to the wavefunctions. Used by the routine that solves the linear system. cch_psi_all.f90 As ch_psi_all for complex e. Used by gmresolve_all. h_psiq.f90 Calculate h psi for k+q. Compute also S psi. cg_psi.f90 Apply the preconditioning. ccg_psi.f90 A complex preconditioning for gmresolve_all. incdrhoscf.f90 Add the contribution of the computed set of perturbed wavefunction at a given k and for a given perturbation to the perturbed change density. incdrhoscf_nc.f90 As incdrhoscf for the noncollinear/so case. addusdbec.f90 Add the contribution of the computed set of perturbed wavefunctions at a given k and for a given perturbation to the change of the becsum. addusdbec_nc.f90 As addusdbec for the noncollinear/spin-orbit case. addusddens.f90 Add the US/PAW augmentation contribution to the change of the charge density. (Phonon case) addusddense.f90 Add the US/PAW augmentation contribution to the change of the charge density. (Electric field case) dv_of_drho.f90 Compute the change of the SCF potential given the change of the SCF charge density. mix_pot.f90 Mix input and output induced SCF potentials. In the PAW case mixes also dbecsum. newdq.f90 Integrate the augmentation function with the change of the SCF potential (US/PAW case only). In the PAW case add the PAW contribution to the change of the coefficients of the nonlocal potential. The coefficients calculated here are used by adddvscf (phonon case) and adddvepsi_us (electric field case). PW/src/paw_onecenter.f90: (PAW_dpotential) Computes the change of the coefficients on the nonlocal potential due to the perturbation (Only PAW case). ef_shift.f90 Accounts for the change of the Fermi level in metals at the gamma point. (ef_shift_paw) Account also for the change of dbecsum. localdos.f90 Computes the local DOS. addusldos.f90 US contribution to the local DOS.
Routines that calculate the derivative of the xc potential. Note that some of them are also in Module/funct.f90:
setup_dgc.f90 Sets the derivative of the xc functionals needed to calculate the change of the potential. It is called by phq_setup. d2mxc.f90 LDA second derivatives of the xc functional dgradcorr.f90 Change of the GGA part of the xc potential. compute_vsgga.f90 Additional GGA term present in the noncollinear/spin-orbit case.
Routines that deal with the nonlinear core correction (NLCC):
set_drhoc.f90 Fourier transform of the core charge at q+G. Called by phq_setup. addcore.f90 Change of the core charge for a phonon perturbation. Used by dv_of_drho and addnlcc. dynmatcc.f90 NLCC contribution to the dynamical matrix independent from the perturbed wavefunctions. Called by dynmat0. addnlcc.f90 The nlcc part of the dynamical matrix that depends on the perturbed potential. Called by solve_linter.
Frequency dependent polarizability:
polariz.f90 Computes the frequency dependent polarizability, given dpsi.
Dielectric tensor:
dielec.f90 Computes the dielectric tensor, given dpsi.
Born effective charges:
add_zstar_ue.f90 Add the contribution to zue due to dpsi induced by a phonon add_zstar_ue_us.f90 Add the US contribution to zue zstar_eu.f90 Compute zeu from the dpsi induced by an electric field zstar_eu_us.f90 Add the US/PAW contribution to zeu. add_dkmds.f90 Additional terms for the US/PAW Born effective charges psidspsi.f90 Calculate <psi_v'|ds/du|psi_v> add_for_charges.f90 Calculate dS/du P_c [x, H-eS] |psi> addnlcc_zstar_eu_us.f90 Add nlcc contribution to zeu dvkb3.f90 Derivative of beta functions with respect to q and tau.
Raman tensor:
raman.f90 This is the main driver for the raman calculation. It computes the second order response calling solve_e2 and the right hand side calling dvpsi_e2. raman_mat.f90 Computes and writes the raman tensor. dhdrhopsi.f90 Computes Pc [DH,Drho] |psi>. dielec_test.f90 Compute the dielectric constant with the quantities calculated inside dhdrhopsi.
Electro-optic tensor:
el_opt.f90 Computes the electro-optic tensor.
Dynamical matrix:
dynmat0.f90 Driver for the part of the dynamical matrix independent from the perturbation. It calls dynmatcc, d2ionq, and dynmat_us. This routine is called by init_phq. dynmat_us.f90 Expectation value of the second derivative of the local and nonlocal potentials. addusdynmat.f90 US/PAW contribution to the second derivative of the potential. There are terms due to the change of the augmentation function. d2ionq.f90 Ewald contribution. drhodv.f90 Contribution to the dynamical matrix due to the change of the wavefunctions. drhodvnl.f90 Accumulate the contribution to the dynamical matrix due to the change of the wavefunctions (Only the contribution of the nonlocal PP). Called at each k point. drhodvloc.f90 As drhodvnl for the local potential. It can be calculated as an integral of the potential and the induced charge density. drhodvus.f90 A term present only in the US/PAW case. Integral of the induced SCF potential and the change of the charge at fixed wavefunctions. It is called in solve_linter because the induced potential is not available outside. dynmatrix.f90 Is a driver that collects the dynamical matrix, checks if all representations have been calculated, symmetrize the dynamical matrix, computes the matrices rotated in all equivalent q and diagonalizes the matrix. The same is done for zue.
Electron-phonon coupling coefficients:
elphon.f90 This is a driver that in the case trans=.false. reads the induced self-consistent potential and calculates the electron-phonon matrix elements. It reads also the dynamical matrix and diagonalizes it. (readmat) read the dynamical matrix. (elphel) compute the electron-phonon matrix elements. (elphsum) make a sum over the BZ of the square moduli of the el-ph matrix elements and compute phonon linewidths. This routine makes a linear interpolation on k points (still unsettled). Require compatibility between q and k meshes. (elphsum_simple) As elphsum but without the interpolation. It can be used at arbitrary q. el_ph_collect.f90 Collect the electron-phonon matrix elements among pools. clinear.f90
Routines that write the output quantities:
phq_summary.f90 Summarize what has been read from the pw output and what has been calculated by phq_setup. summarize.f90 Write the tensors on output. (summarize_epsilon) write the dielectric tensor. (summarize_zeu) write zeu. (summarize_zue) write zue. (summarize_elopt) write the electro-optic tensor. (summarize_fpol) write the frequency dependent polarizability. write_epsilon_and_zeu.f90 Use the routines of summarize, but contain also old instructions to write the dielectric constant and the Born effective charges in the dynamical matrix file. write_modes.f90 (write_modes_out) This routine writes the modes on output. It is called by set_irr and by phq_summarize. write_qplot_data.f90 Write a file that can be read by plotband with q vectors and phonon frequencies. write_ramtns.f90 Write the raman tensor. write_eigenvectors.f90 Used by matdyn to write the eigenvectors on output. Writes the displacements in several format suited to some molecular graphics programs.
Routines that write on file the induced charge densities:
punch_plot_e.f90 Write the change of the charge due to an electric field. davcio_drho.f90 Write the change of the charge due to a phonon perturbation.
Routines that read or write the .xml files with the partial results:
ph_restart.f90 This file contains many routines to write and read the .xml files that contain the partial results of ph.x. See the section "file produced by ph.x". (ph_writefile) This routine can be called from external routines to write the tensors on file. (ph_readfile) This routine can be called from external routines to read the tensors from file. (check_directory_phsave) This routine tries to read the files in the phsave directory to check what has been already calculated. (check_available_bands) This routine search on the outdir directory for the bands files to see if they have been already calculated. (allocate_grid_variables) This routine allocates space for the variables that control the grid calculation. (destroy_status_run) This routine deallocates the variables that control the grid and the variables allocated by phq_readin or ph_restart. io_dyn_mat.f90 This file contains the routines that read and write the dynamical matrix in .xml format. io_dyn_mat_old.f90 These are the routines that read and write the dynamical matrix in the old format (not .xml).
Routines that read or write the recover file:
phq_recover.f90 This routine reads the recover files and reconstruct the status of the calculation so far. write_rec.f90 This file contains the routine that writes the recover file (in unformatted form). (read_rec) read the recover file.
Symmetrization of induced potentials:
symdvscf.f90 Symmetrize the change of the potentials due to a set of perturbations that form an irreducible representation. syme.f90 Symmetrize the change of potentials due to electric field perturbations. sym_dmag.f90 Symmetrize the change of B_xc due to a set of phonon perturbations. sym_dmage.f90 Symmetrize the change of B_xc due to a set of electric field perturbations syme2.f90 Symmetrize the potential of the second order response.
and parallel routines that collect on a single processor the quantity to symmetrize and call the previous routines:
psymdvscf.f90 Parallel version of symdvscf. psyme.f90 Parallel version of syme. psym_dmag.f90 Parallel version of sym_dmag. psym_dmage.f90 Parallel version of sym_dmage. psyme2.f90 Parallel version of syme2.
Symmetrization of tensors or other quantities:
symdyn_munu.f90 Symmetrize a dynamical matrix on the basis of the modes, transforming it in the cartesian basis and applying symdynph_gq. symdynph_gq.f90 Symmetrize a dynamical matrix written in cartesian coordinates. star_q.f90 Given a q point finds all the q in its star. q2qstar_ph.f90 Generate the dynamical matrix in all the q of the star. rotate_and_add_dyn.f90 Rotate a dynamical matrix with a given symmetry operation. tra_write_matrix.f90 Symmetrize the dynamical matrix written in the basis of the modes, brings it in cartesian form and write it. trntnsc.f90 Transform a complex 2D tensor from the crystal basis to the cartesian basis or vice-versa. sym_def.f90 Symmetrize the change of the Fermi level due to the phonon perturbations. sym_and_write_zue.f90 Symmetrize zue. symm.f90 Symmetrize the electron-phonon coefficients. rotate_pattern_add.f90 These are a set of auxiliary routines that manipulate the dynamical matrix in different forms. See the heading of this matrix to see its capabilities.
Routines that perform the symmetry analysis of the eigenvectors to find to which irreducible representation they belong:
prepare_sym_analysis.f90 Prepare the quantities for the symmetry analysis. symmorphic_or_nzb.f90 A function that checks if symmetry analysis can be carried out. It returns true if q is not at zone border or if the group is symmorphic. find_mode_sym.f90 Symmetry analysis of the modes.
Routines that apply the Clebsch Gordan coefficients for the spin-orbit part of the code:
transform_alphasum_nc.f90 Apply the coefficients to alphasum (no-so case) transform_alphasum_so.f90 Apply the coefficients to alphasum (so case) transform_dbecsum_nc.f90 Apply the coefficients to dbecsum (no-so case) transform_dbecsum_so.f90 Apply the coefficients to dbecsum (so case) transform_int_nc.f90 Apply the coefficients to the integrals (no-so case) transform_int_so.f90 Apply the coefficients to the integrals (so case) set_int12_nc.f90 This is a driver that call the previous routines according to the type of PP.
Routines that apply the gamma_gamma trick:
find_equiv_sites.f90 generate_dynamical_matrix_c.f90 generate_effective_charges_c.f90 set_asr_c.f90
Miscellaneous routines:
print_clock_ph.f90 Print timings info. stop_ph.f90 Stops the phonon code closing all the files. rigid.f90 Used by matdyn and dynmat to compute the long range electrostatic part of the dynamical matrix. dyndia.f90 Diagonalizes the dynamical matrix.
Obsolete routines that are here for compatibility with other codes that might use them:
obsolete.f90
Development routines provided by some developers but still incomplete, or used in proprietary codes not yet in the QE distribution, or added and forgotten:
acfdtest.f90 read_wfc_rspace_and_fwfft.f90 dfile_autoname.f90 dfile_star.f90 rotate_dvscf_star.f90 q_points_wannier.f90 set_dvscf.f90 ep_matrix_element_wannier.f90 io_pattern.f90 cgsolve_all_imfreq.f90 q2qstar.f90 write_matrix.f90 chi_test.f90