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lammps/examples/mdi/series_driver.py
Steve Plimpton 1ee40f8f8f change to tests
2022-03-22 11:11:43 -06:00

271 lines
6.5 KiB
Python

# MDI driver to perform a series of independent calculations
# using LAMMPS as an engine
# Syntax: python3 series_driver.py switch arg switch arg ...
# possible switches:
# -mdi "-role DRIVER ..."
# required switch
# -n 10
# number of calculations to perform, default = 1
# -mode eval/run/min
# style of calculations: single snapshot evals, dynamics, minimization
# default = eval
# -size Nx Ny Nz
# cubic lattice, default = 2 2 2
# -rho 0.75 0.1
# reduced density and random variation thereof, default = 0.75 0.1
# -delta 0.1
# randomly perturb atoms initially by this distance, default 0.0
# -nsteps 100
# number of timesteps in dynamics runs, default = 100
# -temp 1.0
# initial temperature in dynamics runs, default = 1.0
# -tol 0.001
# tolerance for minimizations, default = 0.001
# -seed 12345
# random number seed > 0, default = 12345
import sys,math,random
import mdi
import numpy as np
from mpi4py import MPI
# error message
def error(txt=None):
if txt: raise Exception(txt)
raise Exception("Syntax: python3 series_driver.py switch arg switch arg ...")
# send a LAMMPS input script command to MDI engine
def send_command(cmd):
mdi.MDI_Send_Command("NBYTES",mdicomm)
mdi.MDI_Send(len(cmd),1,mdi.MDI_INT,mdicomm)
mdi.MDI_Send_Command("COMMAND",mdicomm)
mdi.MDI_Send(cmd,len(cmd)+1,mdi.MDI_CHAR,mdicomm)
# parse command-line args
args = sys.argv[1:]
narg = len(args)
mdiarg = 0
ncalc = 1
mode = "eval"
nx = ny = nz = 2
rho = 0.75
rhodelta = 0.1
delta = 0.1
nsteps = 100
tinitial = 1.0
tol = 0.001
seed = 12345
iarg = 0
while iarg < narg:
if args[iarg] == "-mdi":
if iarg+2 > narg: error()
mdiarg = iarg + 1
iarg += 2
elif args[iarg] == "-n":
if iarg+2 > narg: error()
ncalc = int(args[iarg+1])
iarg += 2
elif args[iarg] == "-mode":
if iarg+2 > narg: error()
mode = args[iarg+1]
if mode != "eval" and mode != "run" and mode != "min": error()
iarg += 2
elif args[iarg] == "-size":
if iarg+4 > narg: error()
nx = int(args[iarg+1])
ny = int(args[iarg+2])
nz = int(args[iarg+3])
if nx <= 0 or ny <= 0 or nz <= 0: error()
iarg += 4
elif args[iarg] == "-rho":
if iarg+3 > narg: error()
rho = float(args[iarg+1])
rhodelta = float(args[iarg+2])
if rho-rhodelta <= 0.0: error()
iarg += 3
elif args[iarg] == "-delta":
if iarg+2 > narg: error()
delta = float(args[iarg+1])
if delta < 0.0: error()
iarg += 2
elif args[iarg] == "-nsteps":
if iarg+2 > narg: error()
nsteps = int(args[iarg+1])
if nsteps < 0: error()
iarg += 2
elif args[iarg] == "-temp":
if iarg+2 > narg: error()
tinitial = float(args[iarg+1])
if tinitial < 0.0: error()
iarg += 2
elif args[iarg] == "-tol":
if iarg+2 > narg: error()
tol = float(args[iarg+1])
if tol < 0.0: error()
iarg += 2
elif args[iarg] == "-seed":
if iarg+2 > narg: error()
seed = int(args[iarg+1])
if seed <= 0: error()
iarg += 2
else: error()
if not mdiarg: error()
# initialize MDI Library
mdi.MDI_Init(args[mdiarg])
# MPI communicator for just the driver
world = mdi.MDI_MPI_get_world_comm()
me = world.Get_rank()
nprocs = world.Get_size()
# connect to engine
mdicomm = mdi.MDI_Accept_Communicator()
# allocate vectors for per-atom types, coords, vels, forces
natoms = nx * ny * nz
atypes = np.zeros(natoms,dtype=np.int)
coords = np.zeros(3*natoms,dtype=np.float64)
vels = np.zeros(3*natoms,dtype=np.float64)
forces = np.zeros(3*natoms,dtype=np.float64)
atypes[:] = 1
# initialize RN generator
random.seed(seed)
# loop over sequence of calculations
for icalc in range(ncalc):
# define simulation box
onerho = rho + (random.random()-0.5)*rhodelta;
sigma = pow(1.0/onerho,1.0/3.0)
xlo = ylo = zlo = 0.0
xhi = nx * sigma
yhi = ny * sigma
zhi = nz * sigma
# send simulation box to engine
vec = [xhi-xlo,0.0,0.0] + [0.0,yhi-ylo,0.0] + [0.0,0.0,zhi-zlo]
mdi.MDI_Send_command(">CELL",mdicomm)
mdi.MDI_Send(vec,9,mdi.MDI_DOUBLE,mdicomm)
# create atoms on perfect lattice
m = 0
for k in range(nz):
for j in range(ny):
for i in range(nx):
coords[m] = i * sigma
coords[m+1] = j * sigma
coords[m+2] = k * sigma
m += 3
# perturb lattice
for m in range(3*natoms):
coords[m] += 2.0*random.random()*delta - delta
# define initial velocities
for m in range(3*natoms):
vels[m] = random.random() - 0.5
tcurrent = 0.0
for m in range(3*natoms):
tcurrent += vels[m]*vels[m]
tcurrent /= 3*(natoms-1)
factor = math.sqrt(tinitial/tcurrent)
for m in range(3*natoms):
vels[m] *= factor
# send atoms and their properties to engine
mdi.MDI_Send_command(">NATOMS",mdicomm)
mdi.MDI_Send(natoms,1,mdi.MDI_INT,mdicomm)
mdi.MDI_Send_command(">TYPES",mdicomm)
mdi.MDI_Send(atypes,natoms,mdi.MDI_INT,mdicomm)
mdi.MDI_Send_command(">COORDS",mdicomm)
mdi.MDI_Send(coords,3*natoms,mdi.MDI_DOUBLE,mdicomm)
mdi.MDI_Send_command(">VELOCITIES",mdicomm)
mdi.MDI_Send(vels,3*natoms,mdi.MDI_DOUBLE,mdicomm)
# eval or run or minimize
if mode == "eval":
pass
elif mode == "run":
mdi.MDI_Send_command("@INIT_MD",mdicomm)
mdi.MDI_Send_command(">NITERATE",mdicomm)
mdi.MDI_Send(nsteps,1,mdi.MDI_INT,mdicomm)
mdi.MDI_Send_command("@DEFAULT",mdicomm)
elif mode == "min":
mdi.MDI_Send_command("@INIT_OPTG",mdicomm)
mdi.MDI_Send_command(">TOLERANCE",mdicomm)
params = [1.0e-4,1.0e-4,100.0,100.0]
mdi.MDI_Send(params,4,mdi.MDI_DOUBLE,mdicomm)
mdi.MDI_Send_command("@DEFAULT",mdicomm)
# request potential energy
mdi.MDI_Send_command("<PE",mdicomm)
pe = mdi.MDI_Recv(1,mdi.MDI_DOUBLE,mdicomm)
pe = world.bcast(pe,root=0)
# request virial tensor
mdi.MDI_Send_command("<STRESS",mdicomm)
virial = mdi.MDI_Recv(6,mdi.MDI_DOUBLE,mdicomm)
virial = world.bcast(virial,root=0)
# request forces
mdi.MDI_Send_command("<FORCES",mdicomm)
mdi.MDI_Recv(3*natoms,mdi.MDI_DOUBLE,mdicomm,buf=forces)
world.Bcast(forces,root=0)
# final output from each calculation
# pressure = just virial component, no kinetic component
aveeng = pe/natoms
pressure = (virial[0] + virial[1] + virial[2]) / 3.0
m = 0
fx = fy = fz = 0.0
for i in range(natoms):
fx += forces[m]
fy += forces[m+1]
fz += forces[m+2]
m += 3
fx /= natoms
fy /= natoms
fz /= natoms
line = "Calc %d: eng %7.5g pressure %7.5g aveForce %7.5g %7.5g %7.5g" % \
(icalc+1,aveeng,pressure,fx,fy,fz)
if me == 0: print(line)
# send EXIT command to engine
mdi.MDI_Send_command("EXIT",mdicomm)