I'm not really sure what Gaussian does and why you need the wave function files, so this is might be a partial answer... but, e.g. Psi4 can do geometry optimization with an applied electric field, e.g.

"""

molecule h2o {

0 1

O 0.000000000000 0.000000000000 -0.071143036192

H 0.000000000000 -0.758215806856 0.564545805801

H 0.000000000000 0.758215806856 0.564545805801

}

set {

basis cc-pvdz

d_convergence 10

}

set perturb_h true

set perturb_with dipole

set perturb_dipole [0, 0, 0.01]

optimize(scf')

"""

will run an optimization of the water molecule in the electric field (0, 0, 0.01). If you need to find out how an electric field along any of the axes modifies the minimum geometry, you'll just have to run 6 jobs with different fields, and extract their minimum geometries.

Dear Lehtola,

I will try it. It seems that Psi4 meets the requirement.

I will use some test jobs as soon as possible and if all is fine Psi4 will be used for the real jobs.

One more question:

In the Gaussian script one can specify the optimization, the cartesian coordinates

(required only once) followed by zero.wfn (Field=0) and than

with the link commando you specify all other fields in (+/-)x,y,z direction.

A name.chk file (or name.fchk) is created which ("automatically") transfers the

optimized parameters to the next linked calculations, which means that the output

corrresponds to a singlePoint calculation for each specified field, respectively each *.wfn file.

Can something similar be done in Psi4, I mean,sequential calculations using the same script?

See Gaussian script attached which provides an example.

Thank you

Regards

Dear Lehtola, I am testing Psi4 with existent dat files and all are running well, except your script. I am sending you the output message:

--------------------------------------------------

#! Test wfn in Psi4

"""

molecule h2o {

0 1

O 0.0000 0.0000 -0.07144

H 0.0000 -0.7582 0.56454

H 0.0000 0.7582 0.56454

}

set {

basis cc-pvdz

d_convergence 10

}

set perturb_h true

set perturb_with dipole

set perturb_dipole [0, 0, 0]

optimize(scf')

"""

--------------------------------------------------------------------------

Traceback (most recent call last):

File "./psi4", line 248, in

exec(content)

SyntaxError: invalid syntax (, line 23)

*** Psi4 encountered an error. Buy a developer more coffee!

*** Resources and help at github.com/psi4/psi4.

------------message that is shown on therminal

bcramer@Bolzmann:~/psi4-workdir$ /usr/local/Psi4conda_Py36/lib/python3.6/site-packages/v2rdm_casscf/v2rdm_casscf.so loaded.

Traceback (most recent call last):

File "./psi4", line 248, in

exec(content)

SyntaxError: invalid syntax (, line 23)

-------------------------------------------

This is indeed possible, and is trivial to do in Psi4. Once you have specified the molecule, it will remember it throughout the rest of the file. So, you can just change the field and rerun the optimization, and it will start with the last geometry of the system. Thus, you can run two optimizations with

"""

molecule h2o {

0 1

O 0.000000000000 0.000000000000 -0.071143036192

H 0.000000000000 -0.758215806856 0.564545805801

H 0.000000000000 0.758215806856 0.564545805801

}

set {

basis cc-pvdz

d_convergence 10

}

# Here, we optimize with zero field

optimize('scf')

# Next, optimize with (0, 0, 0.01) field, using zero-field geometry

set perturb_h true

set perturb_with dipole

set perturb_dipole [0, 0, 0.01]

optimize('scf')

# Second optimization, uses geometry optimized at (0, 0, 0.01) field

set perturb_dipole [0, 0, -0.01]

optimize('scf')

"""

Dear Lehtola,

Psi4 is working fine and I am using your script with some additionals like psi4 " fchk_write" I get the output I need . So the bottle neck in my work is gone and I am considering to include Psi4 as an additional source in my research.

Thank you

Regards