That would be a great feature, I am struggling with these cartesian coordinates in Multiwfn. However, I just found out that Molden2AIM in its newest version (Version 5.0.0 (06/05/2020)) supports cartesian to spherical transformation.

It turns

 96 XX 3(Co) 34 0.87388% 97 YY 3(Co) 34 24.93716% 98 ZZ 3(Co) 34 16.47464% 99 XY 3(Co) 34 3.55180%

into

 86 D 0 3(Co) 34 19.25375% 89 D+2 3(Co) 34 13.69216% 90 D-2 3(Co) 34 4.15096% 91 D 0 3(Co) 35 0.50383%

Thanks! Exactly what I am looking for!

The transformation coefficients can be found in supplemental material of original paper of mwfn format (https://doi.org/10.26434/chemrxiv.11872524)

Thanks for your speedy reply! That is okay. Could you point to the resources of doing the Cartesian (C) to spherical (S) transformation so that I can try implementing one by myself? I would expect the transformation is done as <MOcoeff_C> = <C2S><MOcoeff_S>, so the inverse transformation can be easily done in principle? Thanks!

Unfortunately, Multiwfn can only convert spherical basis functions to Cartesian ones, while converting Cartesian basis functions to spherical ones is not supported.

Dear Multiwfn developers,

I have a molden file generated by a quantum chemistry software in which the basis set is represented in Cartesian coordinates (i.e., 6 basis functions for d orbitals). I would like to convert this molden file into the .gbw file via orca_2mkl too as ORCA's initial guess wfn (I have a script to convert molden file to molekel file first). However, this conversion failed because ORCA by default only accepts basis sets in spherical representation (i.e., 5 basis functions for d orbitals). I am wondering is there any tools in multiwfn that can take the molden file with Cartesian basis set as input, convert the information (MO coefficients, occupation numbers, etc.) to that of a corresponding spherical basis set, and finally output the new molden file?

Best regards,
Chenru