Usage of SystemCalculator Instance

We here provide some examples on how to run the code with system calculator. Let us consider a very simple inputfile and a small system, that can be give from file and from a dictionary of atomic positions.

from BigDFT import Inputfiles as I
from BigDFT.Calculators import SystemCalculator
from futile.Utils import write
inp=I.Inputfile()
inp.set_xc('PBE')
inp.set_rmult(coarse=3) #very very little, only for test
inp

{'dft': {'ixc': 'PBE', 'rmult': [3, 8.0]}}

We initalize the SystemCalculator instance by specifying the number of OMP threads and the command to be used for the mpirun calculation.

code=SystemCalculator(omp=1,mpi_run='mpirun -np 2')

Initialize a Calculator with OMP_NUM_THREADS=1 and command mpirun -np 2 /home/marco/Applications/BigDFT/binaries/v1.8.3/install/bin/bigdft

Let us define the function for validating the runs:

def validate_run(inputfile,logfile):
    """
    Checks that the inputfile and the logfiles exists and have recent dates.
    """
    import os.path as P
    from futile.Utils import write,file_time
    from time import time
    write('Input and log existing',P.isfile(inputfile),P.isfile(logfile))
    write('Created since',time()-file_time(inputfile),time()-file_time(logfile))

Basic run, no name and atomic positions from a file:

result=code.run(input=inp,posinp='CH4_posinp.xyz')
write('Energy',result.energy)
validate_run('input.yaml','log.yaml')

Creating the yaml input file "./input.yaml"
Executing command:  mpirun -np 2 /home/marco/Applications/BigDFT/binaries/v1.8.3/install/bin/bigdft
Energy -8.09733985003
Input and log existing True True
Created since 2.02708792686 0.0871000289917

Now let us provide a naming scheme. The inputfile and the logfile will have different names:

result=code.run(input=inp,posinp='CH4_posinp.xyz',name='test1')
write('Energy',result.energy)
validate_run('test1.yaml','log-test1.yaml')

Creating the yaml input file "./test1.yaml"
Executing command:  mpirun -np 2 /home/marco/Applications/BigDFT/binaries/v1.8.3/install/bin/bigdft -n test1
Energy -8.09733985003
Input and log existing True True
Created since 1.93355202675 0.0256290435791

Let us now provide a output directory. To do that there are two different options: * Provide the outdir command to the bigdft executable * Define a run_dir for the run of the calculator instance. The difference between the two is the position of the input files. In the first case they will be in the Current Working Directory, whereas in the second one they will be placed in the run_directory.

from os.path import join as j
#first case
result=code.run(input=inp,posinp='CH4_posinp.xyz',name='test2',outdir='out1')
write('Energy',result.energy)
validate_run('test2.yaml',j('out1','log-test2.yaml'))
#second case
result=code.run(input=inp,posinp='CH4_posinp.xyz',name='test3',run_dir='out2')
write('Energy',result.energy)
validate_run(j('out2','test3.yaml'),j('out2','log-test3.yaml'))
#combine the two
result=code.run(input=inp,posinp='CH4_posinp.xyz',name='test4',run_dir='out3',outdir='out4')
write('Energy',result.energy)
validate_run(j('out3','test4.yaml'),j('out3','out4','log-test4.yaml'))

Creating the yaml input file "./test2.yaml"
Executing command:  mpirun -np 2 /home/marco/Applications/BigDFT/binaries/v1.8.3/install/bin/bigdft -n test2 -d out1
Energy -8.09733985003
Input and log existing True True
Created since 1.86937189102 0.0214099884033
Create the sub-directory 'out2'
Copy the posinp file 'CH4_posinp.xyz' into 'out2'
Creating the yaml input file "out2/test3.yaml"
Run directory out2
Executing command:  mpirun -np 2 /home/marco/Applications/BigDFT/binaries/v1.8.3/install/bin/bigdft -n test3
Energy -8.06514886077
Input and log existing True True
Created since 1.96282911301 0.0228381156921
Create the sub-directory 'out3'
Copy the posinp file 'CH4_posinp.xyz' into 'out3'
Creating the yaml input file "out3/test4.yaml"
Run directory out3
Executing command:  mpirun -np 2 /home/marco/Applications/BigDFT/binaries/v1.8.3/install/bin/bigdft -n test4 -d out4
Energy -8.06514886077
Input and log existing True True
Created since 1.95026421547 0.0226290225983