Quantum Espresso源码浅尝

下载QE源码，简单阅读分析，由于是f90写的，与主流的程序开发不同，一般人很难看懂，调试。仅供有兴趣的人员，在黑盒操作的基础上研究。

 

## PACKAGES

 

- PWscf: structural optimisation and molecular dynamics on the electronic ground state, with self-consistent solution of DFT equations;

- CP: Car-Parrinello molecular dynamics;

- PHonon: vibrational and dielectric properties from DFPT (Density-Functional Perturbation Theory);

- TD-DFPT: spectra from Time-dependent DFPT;

- HP: calculation of Hubbard parameters from DFPT;

- EPW: calculation of electron-phonon coefficients in metals;

- PWCOND: ballistic transport;

- XSpectra: calculation of X-ray absorption spectra;

- PWneb: reaction pathways and transition states with the Nudged Elastic Band method;

- GWL: many-body perturbation theory in the GW approach using ultra-localised Wannier functions and Lanczos chains.

 

 

## Modular libraries

The following libraries have been isolated and partially encapsulated in view of their release for usage in other codes as well:

 

- UtilXlib: performing basic MPI handling, error handling, timing handling.

- FFTXlib: parallel (MPI and OpenMP) distributed three-dimensional FFTs, performing also load-balanced distribution of data (plane waves, G-vectors and real-space grids) across processors.

- LAXlib: parallel distributed dense-matrix diagonalization, using ELPA, SCALapack, or a custom algorithm.

- KS Solver: parallel iterative diagonalization for the Kohn-Sham Hamiltonian (represented as an operator),using block Davidson and band-by-band or block Conjugate-Gradient algorithms.

- LRlib: performs a variety of tasks connected with (time-dependent) DFPT, to be used also in connection with Many-Body Perturbation Theory.

- upflib: pseudopotential-related code