start basopt

# Optimize a primitive basis set for He starting from the sto-3g
# set of exponents using the quasi-Newton optimizer.

# In order to enforce the sign constraint on the exponents
# perform an unconstrained minimization on the variables z[i]
# where exponent[i]=z[i]*z[i].

geometry 
  He 0 0 0
end

scf
  thresh 1e-8
  tol2e 1e-12
end

print none

python noprint
  from __future__ import print_function
  
  from mathutil import *

  # It should only be necessary to modify these three lines for 
  # your system ... the exponents will be subsitituted in order

  basis = 'basis noprint; He s; %f 1.0; He s; %f 1.0; He s; %f 1.0; end\n'
  exponents = [6.362421390, 1.158923000, 0.313649790]
  theory = 'scf'


  # Should not need to modify below here
  def energy(z):
    exponents = array('d',range(len(z)))
    for i in range(len(z)):
      exponents[i] = z[i]*z[i]
    input_parse(basis % tuple(exponents))
    return task_energy(theory)

  def printexp(z):
    print("\n Exponents:")
    for i in range(len(z)):
      print (" %14.8f" % (z[i]*z[i])),
      if ((i+1)%5) == 0:
        print("")
    print(" ")

  z = array('d',exponents)
  for i in range(len(z)):
    z[i] = sqrt(exponents[i])

  #cgmin2(energy, z, 5e-4, 1e-9, printexp)
  quasinr(energy, z, 5e-4, 1e-9, printexp)
    
end

task python