NWChem/contrib/python/coulombfitting.atom.nw

start coulombfitting

# This python program generates Coulomb fitting basis sets 
# for an atom using a uhf scf or dft wave function, both
# with Hartree-Fock exchange
#
# Optimize an even tempered like set of primitive functions 
# for an atom and return list of exponents and contraction 
# coefficients

# exp[i+1] = exp[i] * beta * (1 + gamma * (i^2/(n+1)^2)
#
# with i = 0,...,n-2

# Input block after the python call:
#   run_type = "scf" or "dft"
#   atom   = which atom to optimize for
#   charge = atomic charge
#   nopen  = nr of open shells (hence 2S)
#   basis  = name of basis in nwchem library
#   ecp    = name of ecp in nwchem library
#   l      = maximum angular momentum
#   n      = list with nr of exponents per l-value
#   freeze = l-values that should not be optimized 
#            0 = optimize
#            1 = not optimize
#   exp0   = list with exp[0] a for expansion per l-value, see formula above
#   beta   = list with beta a for expansion per l-value, see formula above
#   gamma  = list with gamma a for expansion per l-value, see formula above

set tolguess 1e-10

set lindep:n_dep 0

set int:acc_std 1e-25

print none

python
  from __future__ import print_function
  from mathutil import *

  run_type = "scf"
  atom = "Be"
  charge = 0
  nopen = 0
  basis = "Ahlrichs_pVDZ"
  ecp = ""
  l = 2
  n = [9,5,2]
  freeze =  [0,1,1]
  exp0 =  [0.25,0.40,0.60]
  beta =  [1.44,1.44,1.44]
  gamma = [1.00,1.00,1.00]

  def nr_lvalue_list(k):
    nr = -1
    for i in range(0,k+1):
        if (n[i]>0 and freeze[i]<1):
           nr = nr + 1
    return (nr)
  
  def put_exp0_beta_gamma():
    z = zerovector(3*(nr_lvalue_list(l)+1))
    for i in range(0,l+1):
       if (n[i]>0 and freeze[i]<1):
          nr = nr_lvalue_list(i)
          z[0+3*nr] = sqrt(exp0[i] - 0.000001)
          z[1+3*nr] = sqrt(beta[i] - 0.000001)
          z[2+3*nr] = sqrt(gamma[i] - 0.000001)
    return (z)

  def get_exp0_beta_gamma(z,k):
    if (freeze[k]>0):
       exp0_n  = exp0[k]
       beta_n  = beta[k]
       gamma_n = gamma[k]
    else:
       nr = nr_lvalue_list(k)
       exp0_n  = z[0+3*nr]*z[0+3*nr]+0.000001
       beta_n  = z[1+3*nr]*z[1+3*nr]+0.000001
       gamma_n = z[2+3*nr]*z[2+3*nr]+0.000001
    return (exp0_n, beta_n, gamma_n)

  def make_exp(z):
    exponents = zeromatrix(max(n),l+1)
    for j in range(0,l+1):
       (exp0_n, beta_n, gamma_n) = get_exp0_beta_gamma(z,j)
       exponents[0][j] = exp0_n
       for i in range(0,n[j]-1):
          ee = exponents[i][j] * beta_n
          ee = ee * (1 + gamma_n * i * i / ((n[j] + 1) * (n[j] + 1)) )
          exponents[i+1][j] = ee          
    return exponents

  def type_setup(type):
    if (type == "scf"):
       string = "scf; ri-scf coulomb; uhf; vectors input start.movecs output final.movecs;"
       string = string + ('nopen %i; maxiter 1; thresh 1e-8; end\n\n') % (nopen)
    else:
       string = "dft; xc hfexch 1.0; grid xfine; tolerances tight; odft;"
       string = string + "vectors input start.movecs output final.movecs;"
       string = string + ('mult %i; iterations 1; convergence energy 1e-8; end\n\n') % (nopen+1)
    return string
  
  def ref_energy():
    if (run_type == "scf"):
       return task_coulomb_ref('scf')
    else:
       return task_coulomb_ref('dft')
       
  def energy(z):
    function_type = ["s", "p", "d", "f", "g", "h", "i"]
    exponents = make_exp(z)
    basis = 'basis "riscf basis" spherical noprint;'
    for j in range(0,l+1):
       for i in range(0,n[j]):
          basis = basis + ('%s %s ; %f 1;' % (atom, function_type[j], exponents[i][j]))
    if (run_type == "scf"):
       basis = basis + "end\n\n" + type_setup('scf')
       input_parse(basis)
       return task_coulomb('scf')
    else:
       basis = basis + "end\n\n" + type_setup('dft')
       input_parse(basis)
       return task_coulomb('dft')
        
  def printexp(z):
    function_type = ["s", "p", "d", "f", "g", "h", "i"]
    exponents = make_exp(z)
    print(' Exponents:')
    for j in range(0,l+1):
        print("%s - functions" % (function_type[j]))
        for i in range(0,n[j]):
          print(" %14.8f" % exponents[i][j])
        print("")
    print(" ")

  # Setup list of variables to be optimized

  z = zerovector(3*(nr_lvalue_list(l)+1))
  z = put_exp0_beta_gamma()

  # Place geometry, basis, and (possibly) ecp into input / rtdb
 
  calc_setup = "geometry;"
  calc_setup = calc_setup + ('%s  0  0  0; end\n\n') % (atom)
  calc_setup = calc_setup + ('basis spherical noprint; %s library %s; end\n\n') % (atom, basis)
  if (ecp != ""):
     calc_setup = calc_setup + ('ecp spherical noprint; %s library %s; end\n\n') % (atom,ecp)
  calc_setup = calc_setup + ('charge %i \n\n') % (charge)
  input_parse(calc_setup)
  
  # Calculate reference energy without Coulomb fitting
  #
  # First setup for scf or dft
 
  if (run_type == "scf"):
     string = "scf; uhf; vectors output start.movecs;"
     string = string + ('nopen %i; maxiter 100; thresh 1e-8; end\n\n') % (nopen)
  else:
     string = "dft; xc hfexch 1.0; grid xfine; tolerances tight; odft;"
     string = string + ('mult %i; vectors output start.movecs;') % (nopen+1)
     string = string + "iterations 100; convergence energy 1e-8; end\n\n"
  input_parse(string)
  reference = ref_energy()

  # Optimize fitting basis set
 
  (value,z) = quasinr(energy, z, 1e-5, 1e-12, printexp)

  # Print the final results
 
  print('\n\n    Results\n')
  print('  l   n     exp0       beta       gamma   ')
  print(' --- ---  ---------  ---------  --------- ')
  for j in range(0,l+1):
     (exp0_n, beta_n, gamma_n) = get_exp0_beta_gamma(z,j)
     print('%4i %4i %12.6f %10.6f %10.6f' % (j, n[j], exp0_n, beta_n, gamma_n))
  print('\n Final energy difference = %12.6f' % value)
  print('\n Energy without Coulomb fitting = %12.6f' % reference)
  printexp(z)
end

task python