Dalton forum

This is of course the Dalton forum, but certainly CFOUR can do open-shell coupled-cluster calculations, which Dalton cannot. (Dalton can do triplet excited states using a closed-shell coupled-cluster reference function, but O 2 is awkward because neither of the low-lying singlets is a closed-shell s...

You can certainly do CI calculations rather than MCSCF: this is described in the manual. And using your proposed approach of doing MCSCF, saving the orbitals, and then using them as input into a CI calculation will work. That said, it is not clear to me that this is a fruitful approach, unless you a...

I don't think you can "restart" with a different basis. I think the word is intended to be interpreted literally, as in picking up a calculation at the point where it has stopped (or died) and continuing it from there, possibly with a minor change to the input parameters. I can imagine that projecti...

Another aspect to consider is what sort of molecules and electronic states you are interested in. If the systems are composed of lighter atoms, like a typical organic molecule, then you should consider the AMFI approximation for dealing with the spin-orbit terms (this is described in the manual). AM...

(I am commenting here only on your issues with Dalton2018) I am not sure that tests running out of time is a cause for concern, but out of eight failures in your posted output there are three that are not timeouts. It is difficult to comment on what may be wrong without knowing why those tests faile...

This has nothing to do with your problem, I am sure, but I just wanted to point out that unless you are running a test calculation, or trying to reproduce other work, your basis set choice (6-31G**) is not a good one. To say the least. This set is poor for first- and second-row atoms (it is not even...

I am a little surprised at your response after a genuine attempt to understand what it was you were posting about. I have no interest whatsoever in the hyperpolarizability of anything, at least not at present so there is certainly no question for me to answer! I am just trying to understand what you...

Then I think you do not need orbital energies because you will get this information from the natural orbital occupation numbers. My usual rules of thumb (your mileage may vary... and others might apply different criteria) are: If the occupation is 1) Very close to 2, like 1.98x or similar, the orbit...

Good luck with it! I think if you get SAPT to work with some programs but it still doesn't work with the current Dalton, then someone on the forum may be able to give you some help (although this is not certain).

Best regards
Pete

What information were you hoping to obtain from "orbital energies" (which, as you have been told, are not well defined for MCSCF)?

Best regards
Pete

Are you certain that Dalton2.0 is required and that no later version will work? It may be that the SAPT webpage (which I have not checked) means only that a version later than Dalton1.x is required, in which case the current version may be satisfactory. It may be that someone can supply you with a v...

With all due respect, this does not answer my question. I did not ask what the experimental value was, I asked whether you were asserting that different programs gave different results for what should be the same calculation. If that is the case, then there is presumably a problem with one or more o...

The fact that there was an output file attached did not come up for me when I looked at the earlier posting, so I was not aware you'd posted it. Sorry about that because I could have replied sooner if I had seen it before! The statistics presented after the RASSCF calculation converged explain the t...

I am a bit lost now as to what your question is, or at least what it seems to have evolved into. Are you asserting that three programs that claim to do exactly the same calculation give different results? If so there are ways to check this (certainly in the static limit this can be done using finite...

It would of value to see exactly what calculation you are trying to run on O2 that converges slowly and that takes a very substantial amount of time (for a diatomic). It might be possible to improve on this. I do not see that reducing integral accuracy (which is not a very good idea for reasons ment...

This may be too late to be useful to you, but I would make the following points: 1) Calculated polarizabilities and particularly hyperpolarizabilities are usually strongly affected by the inclusion of correlation effects. Hartree-Fock and most DFT functionals that I am aware of will only give sensib...

If you wish to calculate (static) polarizabilities at the NEVPT2 level you could consider adding a small finite electric field to the Hamiltonian (this is documented in the manual), calculating the polarizability components by finite differences of energies. But this is only feasible for the static ...

It appears my earlier posting was not clear. It does not matter which correlation treatment you use (you said you would try ACCD, but what I write here applies to any treatment of dynamical electron correlation, starting with MP2 and climaxing with full CI): unless you have a basis set with polariza...

First, would you please not post outputs or output fragments inline! It makes messages very difficult to read in some browsers and on some machines. There are perfectly good mechanisms for attaching files. Second, atomic units are a system of units, like SI. In a. u. certain fundamental quantities a...

All of the fundamental constants needed for units conversion are listed in the file DALTON/include/codata.h in the Dalton source tree. My experience is that it is usually better to calculate the conversion factors oneself from these, rather than rely on other people who may not be using the same dat...

I would be surprised if you need the STATE keyword, given that you are running with symmetry, because I am fairly certain that the first excited state of CO 2 is a different symmetry to the ground state (I think perhaps a Pi u state). This would then be the lowest state in symmetry 2 or 3. In that c...

This is unfortunately the smallest example we have immediately to hand. I can try to fudge something together but I wanted to give you something sooner rather than later. This is old-skool with an explicit ghost basis, not using the fancy INTERACTIONENERGY option in LSDalton. Although this will run ...

The spin-orbit operator can be thought of as having the action DeltaS = +/-1 when operating on a given wave function. If that wave function has S=0 then there is only one result: DeltaS=+1 (so singlet/triplet coupling). If you operate on a wave function with S other than zero (or 1/2) you can get re...

I am confused about how to run a counterpoise-corrected calculation of BSSE in a solvent. All attempts to use SubSystems and .INTERACTIONENERGY fail with segfaults. But if we explicitly construct a calculation with the ghost basis using Phantom, then the calculation fails to converge in the SCF but ...

As far as I know there is no OpenMP parallelism in Dalton, so that possibility is not relevant. Quite a lot of the code for calculating molecular properties is MPI parallelized and exploiting that will give a speed-up for some calculations. However, there is, as the output indicates, no MPI function...