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I haven't installed Orca in windows lately, but there are installation binaries in the orca forum. It is likely also explained in the manual. It cannot be hard, it's probably just running the executable for the installation (which will likely do everything), or alternatively copying the files into a folder, and adding the folder of orca to the system path. That can be searched online.

@@patrickdedetemo472 probably yes. You can calculate a small cluster of atoms or molecules representing your solid or liquid, your isolated molecule and the same cluster plus that molecule absorbed. How realistic the number will be will depend on how large the section of material is, and the type of interaction. The stronger the interaction the more accurate the estimation will be.

@@BrentLeVasseur I'm sorry but that sounds like pseudoscience. I have never heard of cold electricity, but electricity at low currents and voltages is indeed used for healing purposes or for desensitisation of muscles in physical therapy. But the rest doesn't sound scientific. Entropy is a strictly positive quantity. Entropy changes can be negative for a system but the total entropy change in the system plus environment is always positive.

@@niconeuman It’s not pseudoscience. It’s a real phenomena that can easily be reproduced in a lab or even at home using off the shelf wires and components. And it would seem that entropy is not strictly positive, because what seems to be happening is time reversal within a localized field around the electrons.

@@niconeuman The phenomena was first discovered by Nikola Tesla with his radiant energy experiments. They employ an open circuit spark gap where a resonant coil is pulsed with high voltage DC current. You can google his hairpin circuit patent as an example. That circuit will produce cold electricity.

Hay varios archivos de salida. Uno tiene una terminación finalensemble y creo que es .xyz ese se puede abrir con Chemcraft y no se si Avogadro. Contiene todas las estructuras

@@niconeuman Muchas gracias, los voy a revisar :D

I'm sorry, but I don't know how to do that type of calculation.

@@niconeuman it's fine keep posting.✨✨

@@andrel3399 yes, what I actually plotted on the third step was deexcitation. May be fluorescence or another process. Phosphorence I didn't include. Hard to show the difference in this kind of animation

the input is a standard calculation with PBE0. it was an optimization from which I took the orbitals. all the magic was done in Chemcraft and then PowerPoint. it is not easy to explain in a post. I will make a video at some point, but it is not that simple to make.

@@niconeuman 👍

Yes please upload the full video ​@niconeuman

@@zakirullah9939 I'll try! I have a lot of work next week!

@@MaríaMartinaVegaGarcía uso Chemcraft. Me gusta más que Avogadro.

También podrías usar ChimeraX, es gratuita y visualmente es muy buena, con esa puedes ver los modos normales y orbitales moleculares

@@kimist42 unfortunately I don't know. I run everything in Linux. I'm not sure that it works in windows, but in any case you have to configure a couple things more. It's better to ask the XTB developers about that.

Were you able to solve your problem? Did you paste "otool_xtb" in same folder that orca?

@@danielbahena3866 Yes, it was working fine! Goat was not really what I was looking for 😅

lo corrí en Linux, porque uso un clúster HPC para todos mis cálculos. hace un tiempo tenía una versión de Windows para probar en mí máquina pero últimamente hago todo directo en el clúster. a qué otro método te referis? GOAT puede usar cualquier método, pero se vuelve más lento.

@@jimitpatel5651 whenever you change the charge you have to change the multiplicity accordingly. You may have a singlet charged species and a doublet neutral one.

@@niconeuman Thanks for the reply! I am using single charged species as my model has 1 unpaired electron and according to the formula of multiplicity which is 2S+1, the multiplicity should be 2 and thats what I am using.

​@@jimitpatel5651 if you get an error regarding multiplicity, check that you are not missing or have extra H. Sometimes drawing software autocompletes H atoms and it gets it wrong.

These are difficult problems to solve. First, it depends on the total charge and therefore on the oxidation states of the atoms. If you have 6 Cu(0) atoms, their valence configurations are 3d10 4s1 (right?). So in principle you would need an active space of 6 x 6 orbitals and 6 x 11 electrons, which is quite large. The number of unpaired electrons is even, so you would have S(S+1)= 1, 3, 5, 7, etc, and you would need to calculate all this possibilities to see which ones are lower in energy. You will likely be unable to do this without approximations. So you could try an active space of 6 orbitals and 6 electrons, and test the lower allowable multiplicities. If that gives you different combinations of 4s orbitals, you are on a good track. Then you can increase it to 12 orb and 18 electrons, so you will get one 3d and one 4s orbital for each atom. But you will have to investigate further and see what happens. Of course if you have charged clusters you just add or subtract electrons from the active space, and change the multiplicity accordingly. The nroots is the number of excited states you want. It depends on what properties you would like to calculate. For a ground state calculation you just need one, but that is sometimes hard to converge. You can start with 6 or 12 roots, and see what you get (UV/vis transitions for example). And please use NEVPT2 or an equivalent perturbative correction. CASSCF alone is not accurate for energies.

Thank you very much, Nicolas!

@@priyambharadwaz5956 yes it is possible. You just need the xyz coordinates. I don't think you can use the DFT orbitals from Gaussian as guess for the CASSCF, but you don't really need that nowadays.

@@niconeuman you mean I dont to provide orbital guess for CASSCF in Gaussian, if not then how to do that. Does it automatically read orbital guess?

@@priyambharadwaz5956 I don't think Orca will be able to read gaussian files at all. However, you don't usually need to start from other orbitals in Orca, because the CASSCF procedure is really good and can make a good guess by itself and find good orbitals. In case it doesn't, you can plot the orbitals from the first CASSCF calculation, look at them, and make a second CASSCF calculation where you read the .gbw file from the first one, and use the "rotate" keyword to bring orbitals from the inactive and virtual spaces into the active space. I explain how to do that in this video, but also in the manual it is explained clearly. Nowadays doing CASSCF with Orca is quite easy and fast, unless you have a very large active space.

@@juancamilorodriguezbetanco4079 this looks like a bug with the new Orca release. I don't know the cause, but you can ask in the forum. They will be able to help you

I agree that the experiment is correct. DFT will only roughly reproduce bond lengths and angles unless the chemical environment is realistic. in crystals it's the packing. I will eventually study if I can optimize a cluster of molecules in the crystal and see how much of a difference it makes.

You have to use EasySpin, in Matlab. And you have to define the spin system (electron spins, nuclei, etc), input the g-values, A-values and define other things. It is not too hard. There's an orca2easyspin application, but I have never used it.

Yes you can calculate the Gibbs free energy with all the corrections including solvatiob, for the molecule in each oxidation step. Then you subtract them and obtain a DeltaG which is related to an absolute potential. In order to transform it into a relative potential you do the exact same procedure for your standard (Fc/Fc+) and subtract both absolute potentials. That works well for estimating experimental redox potentials, as long as the chemistry of your species is correct. Depending on your system solvation can be very important.

@@niconeuman thank you very much for your answer, i'll do that.

@@RaeedAlmarei there are too many new features. I will talk about a few of them in upcoming videos.

Hi, there are many different types of calculations and a huge number of options for each type. If you look in the Orca Manual there are many examples. There is an Orca input library also. I have 2 or 3 videos on CASSCF calculations which are ab initio, if that is what you want.

Thanks for the nice comment and glad you liked the video!

@@Vinti1031 there are many ways. The Homo-Lumo gap is the difference between the energies of the orbitals. If you open any output file from Orca in Avogadro you will see those values. You can also open the file with a text editor, search for orbital energies and search for the orbitals manually. It depends on which method you want to use. If you watch other videos you will see many examples of different types of calculations, which may give you a better idea. But I have not covered this specifically in any video.

hi, I think so. you would have to do TDDFT and choose an excited state using iroot 1 or something like that. there may be difficulties but you could try it. how to do excited state optimizations is described in the manual

this script will not read .spc files. it works with an ASCII file. you can try eprload, which is an Easyspin function, but it was one of the functions that didn't always work, due to incompatibilities in Octave.

If you just want to plot the orbitals you can do that with Avogadro or IBOView. But for other things you may need Chemcraft. It is unfortunately not free.

@@niconeuman thank you, trying out so far not. I guess I dont need any particular output for natural orbital? just a frequencies calculation right?

@@jouteur13 I'm not sure. You have to request that orca prints the NBOs, but I haven't checked what happens in Chemcraft if you have two sets of orbitals, if it will let you choose or it will pick one by default.

@@niconeuman right I need the largeprint request .thank you

I can't put my email here, but you can find me easily with a Google search. in some of the videos you will see references to my published work. many people contact me through other social networks

there are different ways. some of them can be made in water following the procedure by Rohand, Dehaen, Arkivoc, 2006 (you can find it with that info on GS) there are other methods in neat Pyrrole, which are better for hydrophobic or electron donating aldehydes. I don't have the reference at hand, but search the work by Lindsey on JOC around 2000, Gryko also.

Hi, thanks for the suggestion. I have done this but I didn't know they were called Fukui functions. I am quite busy lately, so I don't know when I will have the time. But there is a good tutorial on this in here: www.orcasoftware.de/tutorials_orca/react/FUKUI.html Basically you have to export the electron density for a cation, neutral and anion with the same starting structure, and then you can subtract the densities in chemcraft. I am not sure if this can be done in Avogadro. I will check. If not, I made long ago an Octave script to read and subtract cube files, but it was not meant to reexport the results as a cube file. But I'm sure there has to be some simple program for doing operations on cube files (they are simply lists of numbers in a particular order)

I'm sorry, but that is from an unfinished project, which I can't share. But what do you need? the input instructions for CASSCF are well covered in the CASSCF tutorial that can be found in the downloads section in the Orca Forum. Also on the Orca manual. There are many options, but the simple ones are covered in many examples.

@@niconeuman Dear Nicolas, Thank you for the answer. I actually managed to do it. One question, being a perturbation method, does it have any parameters related to energy level shifting (like CASPT2, for instance)? Because the energies I've obtained are around 0.5/0.8 eV below what I expected. I know that perturbation theory allows energy to lay below the "exact" value, but I was wondering if there are any parameters that I can apply in order to try to make it more accurate. Again, thanks for the attention and the answer.

if you have an even number of electrons you can only have spin multiplicities of 1, 3, 5, etc, which are odd. so either your total charge is wrong, or you are asking for a doublet when you should have a singlet or triplet, or perhaps you have more or less atoms than you think. most likely, if you took your coordinates from a crystal structure, you may have missing or extra H atoms. or you could have a disorder which gives you some extra atoms you have to delete.

I do have pictures, but you can see them in my paper from 2020, Inorg. chem., Neuman, Albold, Sarkar et al. corroles are purple or blue or green depending on the substituents and the solvent. in less polar solvents they are more blue, in more polar solvents they are more green.

we are synthesising di-pyromethane for formation of corrole. so is it yellow in colour. as our sir said. but we are getting green colour

sir the procedure we followed were. add benzqldehyde and distilled water . boiled it . and addd hcl . and pyrrole dropwise. and after the organic layer extraction we got green instead of yellow colour. wo what could be the problem, can u help ne

Unfortunately I don't know. The NEB procedure generates a trajectory that is optimized sequentially. There should be an autostart feature, but if there isn't, you can alway copy the .xyz files (I think there is a ...NEB.xyz or similar), and you just replace your starting structures by the more optimized ones from this file (taking care that you know which is the start, end and TS guess structure). That should make the NEB run for a shorter time when restarted, as you have better structures. If you are running NEB-TS and your calculation crashes in the TS part, I highly recommend to split the calculation into two parts. First the NEB, and then a separate OptTS calculation on the NEB saddle point. Or even skip the OptTS and just do freq on the NEB start, end and TS structures. Hope this helps

Were you able to continue your NEB from where it left off? My laptop rebooted and I don't know how to continue without starting from scratch :/

I don't know if Orca has periodic boundaries in its MD module. I would have to check. in geometry optimizations it doesn't, so the molecules can fly away. that can happen if the starting structure has some atoms which are too close, and I think it can happen if the integration step in the molecular dynamics is too long. I had that problem a couple of times but not lately. I should check the manual to see if I'm missing something in the MD module.

you can search in Google for Orca Forum Kofo, and you will find the forum. you have to register and in there there is a Downloads section where you can download Orca and I think also Avogadro. even if I gave you the links you would have to register first to download.

@@niconeuman Thank you sir

I haven't looked at this yet. I assume it is possible, because you can read at any point in the job different xyz files, and you can set each calculation in the compound script to output files with a certain name. For example you can use %base "fragment1" in the first step and then use * xyzfile 0 1 fragment1.xyz in another step. And you can basically do whatever you want with those calculations. if you want to run single points on two fragments of a molecule, you would have to manually create the xyz files for each fragment and the entire molecule. Then you can use orca_mergefrag to join the wavefunction files (.gbw) of each fragment and read that as guess for the complete calculation. I don't know if this is what you were asking for.

Can you post the error you get? And the casscf part of your input file?

@@niconeuman CASSCF Input: !def2-svp nofrozencore PAtom %casscf nel 6 norb 6 mult 1 nroots 2 PTMethod FIC-CASPT2 end end * xyz 0 1 N 0.0 0.0 0.0 N 0.0 0.0 1.09768 * Error : Unknown identifier in [CASSCF] block line 6 : Last token : PTMETHOD [file orca_main/maininp1.cpp, line 8873]:

@@niconeuman Input: !def2-svp nofrozencore PAtom %casscf nel 6 norb 6 mult 1 nroots 2 PTMethod FIC-CASPT2 end end * xyz 0 1 N 0.0 0.0 0.0 N 0.0 0.0 1.09768 * Error : Unknown identifier in [CASSCF] block line 6 : Last token : PTMETHOD [file orca_main/maininp1.cpp, line 8873]:

Input: !def2-svp nofrozencore PAtom %casscf nel 6 norb 6 mult 1 nroots 2 PTMethod FIC-CASPT2 end end * xyz 0 1 N 0.0 0.0 0.0 N 0.0 0.0 1.09768 *

Input: !def2-svp nofrozencore PAtom %casscf nel 6 norb 6 mult 1 nroots 2 PTMethod FIC-CASPT2 end end * xyz 0 1 N 0.0 0.0 0.0 N 0.0 0.0 1.09768 * Error : Unknown identifier in [CASSCF] block line 6 : Last token : PTMETHOD [file orca_main/maininp1.cpp, line 8873]:

Generation of fragmented initial guess orbitals for lanthanide complexes would be a very useful tutorial - perhaps it can be done via compound job?

@@MikhailKendin Let me think about it. If you can provide me with an xyz or a cif file for a simple system, small so that it doesn't take that long, it would be great. You are thinking of a CASSCF calculation for magnetic properties? Or something else?

@@niconeuman exactly, I'm interested in CASSCF for orbitally degenerate lanthanides (e.g., Dy3+) and BS-DFT calculations for binuclear gadolinium complexes. I believe that binuclear lanthanide acetates would be valid modelling objects. I can provide you with CIFs within the next few days

Thank you for the advice. I already crystallized that complex and published it in 2021. It was the first DMSO coordinated metallocorrole, and it made it to the cover of EurJIC. Regarding the flat bottomed flask, our roti pump does not reach below 0.15 bar, it has never broken any flask. But I use 99% of the time RBF anyway.

Because I don't have one!

oh sorry I misunderstood what you meant. I do have those (we call them traps) but I didn't have one of the right standard at the moment. i was careful with the vacuum though

@@niconeuman using splash guard is better than clean whole evaporator) BTW "traps" it's also on Ali)

yes, there can be errors. all approaches do and you have to balance your time and objectives. but the tolerances are lower than significant chemical energies. you could do constrained optimisations on several steps of the scan with tighter bounds, but I'm not 100% sure this can be done using multiple xyz feature alone. if your scan has enough points, and the high level energy maximum does not match the low level energy maximum, it would tell you that you should refine a bit more your scan.