Nlcglib is a plugin for sirius providing robust wave-function optimization to q-e-sirius.
Q-e-sirius with the nlcglib plugin can be installed via spack. Please use the
package files provided in this repository (in ./repo), as described below.
git clone -b develop https://github.com/simonpintarelli/nlcglib
# add the spack-repo
spack repo add nlcglib/spack
# build sirius/nlcglib with cuda enabled
spack install q-e-sirius@develop-ristretto%gcc ^sirius+cuda+openmp+nlcglib
# build sirius/nlcglib without cuda
spack install q-e-sirius@develop-ristretto%gcc ^sirius~cuda+openmp+nlcglibNlcglib specific settings are specified in the namelist DIRECT_MINIMIZATION in the QuantumESPRESSO input file. It must be specified after the ELECTRONS namelist. The robust wave-function optimization is run after the SCF loop, taking the last iteration as starting guess. It is recommended to do at least 10 scf (=electron_maxstep) iterations to obtain a good initial guess.
&ELECTRONS ... / &DIRECT_MINIMIZATION nlcg_method = 'mvp2' nlcg_maxiter = 300 nlcg_conv_thr = 1e-9 nlcg_restart = 10 nlcg_bt_step_length = 0.1 nlcg_pseudo_precond = 0.3 nlcg_processing_unit 'none' | 'cpu' | 'gpu' '# default=none, i.e. will run on gpu if there is cuda device /
nlcg_conv_thr has the same meaning as conv_thr in the ELECTRONS namelist of the QE input, but note that nlcg_conv_thr is set to 1e-9 by default, while conv_thr defaults to 1e-6.
The default values should work for most cases, i.e. to enable the robust optimization, simply insert an empty namelist in the QE input file after the ELECTRONS namemlist:
&ELECTRONS ... / &DIRECT_MINIMIZATION /
In this case the default settings will be used (300 iterations max, cg-restart 10, threshold 1e-9).
Currently Gaussian, Fermi-Dirac broadening is supported. The support for Methfessel-Paxton and Marzari-Vanderbilt smearing is experimental.
- Marzari, N., Vanderbilt, D., & Payne, M. C., Ensemble Density-Functional Theory for Ab Initio Molecular Dynamics of Metals and Finite-Temperature Insulators. , 79(7), 1337–1340. http://dx.doi.org/10.1103/PhysRevLett.79.1337
- Freysoldt, C., Boeck, S., & Neugebauer, J. Direct minimization technique for metals in density functional theory. , 79(24), 241103. http://dx.doi.org/10.1103/PhysRevB.79.241103