#! cc3: RHF-CCSD/6-31G** H2O geometry optimization and vibrational frequency
#! analysis by finite-differences of gradients


memory 250 mb

molecule h2o {
  0 1
  O 
  H 1 0.97
  H 1 0.97 2 103.0
}

set globals {
  basis 6-31G**
  r_convergence 10
  e_convergence 10
}

optimize('ccsd')



frequencies('ccsd', dertype=1)
fd_freqs_grad = psi4.wavefunction().frequencies()

frequencies('ccsd', dertype=0)
fd_freqs_energy = psi4.wavefunction().frequencies()

compare_vectors(fd_freqs_grad, fd_freqs_energy, 1, "CCSD Grads vs. Energies Findif (3-pt.) freqs to 0.1 cm^-1")

