Skip to main content

Questions tagged [orca]

For questions about (or involving) the ORCA electronic-structure package.

Filter by
Sorted by
Tagged with
8 votes
3 answers
206 views

Different results from MP2 calculations on same geometry in ORCA

I am trying to do a segmented potential energy scan around a dihedral for a molecule. I have optimized the geometry to a minima, and the scan runs from [-180, 180] in steps of two points at a time. ...
Hemanth Haridas's user avatar
5 votes
2 answers
195 views

OpenMPI not running under SLURM in UBUNTU with ORCA?

I have ORCA 5.0.4, OpenMPI 4.1.1 and SLURM in UBUNTU 22 in a single PC with 16 threads. I have setup this pc and, when I run orca alone, openmpi works. But, when I submit orca through slurm, the ...
Another.Chemist's user avatar
3 votes
1 answer
105 views

Cannot reproduce excitation energies in Orca

I do TD-DFT studies in Orca 5.0.3 on porphyrin system and hence at the very beginning I need to pick functional that reproduce excitation energies. The experimental reported values equal: 691, 656, ...
farmaceut's user avatar
3 votes
0 answers
59 views

How to calculate Gibbs free energy of a reaction involving cations using GFN2-xTB (via ORCA)

I am trying to compare the Gibbs free energy of reactions such as: A + 4K(+) --> B(4+) A + 4Na(+) --> C(4+) A + 4Li(+) --> D(4+) A + 4Ca(2+) --> E(8+) A + 4Mg(2+) --> F(8+) In these ...
P Teeuwen's user avatar
  • 131
2 votes
0 answers
103 views

Error: Cannot open GBW file: TS.gbw

I have a problem with calculating Transition State using NEB-TS. Here is my input file: ...
Jots's user avatar
  • 21
5 votes
2 answers
155 views

Trying to get concurrent results for a TDDFT calculation in Gaussian and ORCA

I am trying to do a simple TDDFT calculation in both Gaussian and ORCA from the exact same reference Geometry. I am using the same functional (making sure to use ...
Uranium238's user avatar
2 votes
0 answers
54 views

How to generate .47 files from ORCA-5.0.3 ? Also, can we analyze the second order perturbation energy analysis within the nbo scheme using GENNBO?

I am using ORCA-5.0.3 as ESS package and our group has also recently purchased nbo7 which is not interfaced with the ESS. I had tried multiple ways to generate .47 file but couldn't succeed and am ...
Hrithik's user avatar
  • 21
4 votes
1 answer
308 views

Syntax Error in ORCA

I keep getting the following error for my orca code: [file orca_main/maininp1.cpp, line 17547]: ERROR: expect a '$', '!', '%', '*' or '[' in the input [file ...
znc204's user avatar
  • 63
5 votes
2 answers
118 views

Reintegrate calculation results from ORCA using finer grid?

I have made a bunch of calculations in ORCA to compare them to results from this paper. The original calculations from this paper were done in TurboMole. I tried to recreate the method as best I could ...
J.Doe's user avatar
  • 493
6 votes
1 answer
101 views

Mathematical model/open source code to obtain displaced geometries along a normal mode from vibrational frequency calculation

I am looking for a mathematical model which will produce the displacement vectors from vibrational frequency calculations. I use ORCA for the calculation of the frequencies and generally use Chemcraft ...
Aritra Mukhopadhyaya's user avatar
7 votes
1 answer
255 views

Do ORCA input files allow for multi-line comments or different comment syntaxes?

I have a self-inflicted problem with the input files that I am generating using RDKit in order to automate my ORCA jobs. I like to keep track of data such as: The ...
J.Doe's user avatar
  • 493
3 votes
1 answer
187 views

UseSym Keyword in ORCA fails to find appropriate number of SALCs

I am trying to run some geometry optimizations in ORCA 5.0.4 and I am using the UseSym keyword to ensure that my molecules retain Cs Symmetry during optimization. ...
J.Doe's user avatar
  • 493
2 votes
1 answer
125 views

ORCA Error: NCalcs not set

I've been getting the following error whenever I use CCSD(T) and the ORCA Forums don't have an answer to this one: ...
znc204's user avatar
  • 63
5 votes
1 answer
323 views

ORCA crashes because of RI approximation?

I am doing a geometry optimization for a cationic imidazolate-zinc complex. I'm trying to run an optimization using this input file. It uses the RI approximation. ORCA seems to be running fine until ...
J.Doe's user avatar
  • 493
4 votes
1 answer
435 views

Kill or let be: Is this calculation stuck or just very slow?

My question is regarding a medium-to-large DLPNO-UCCSD(T)-F12 calculation. I have a ~250 electron system, an open-shell molecule inside a water droplet, and I'm trying to get the total energy, first ...
epalos's user avatar
  • 4,869
3 votes
1 answer
245 views

Calculating Reorganisation energy using ORCA

I wondered if anyone knows of a way to calculate the reorganization energy of a molecule utilizing orca 5.0.3.
Madeleine Fisher's user avatar
3 votes
1 answer
540 views

Repeated Error message ORCA

I am repeatedly getting the error message: [file orca_main/maininp1.cpp, line 17547]: ERROR: expect a '$', '!', '%', '*' or '[' in the input when I run my Orca script. My inp file looks like: ...
Madeleine Fisher's user avatar
2 votes
1 answer
212 views

Calculating vertical excitation energies at the DLPNO-STEOM-CCSD Theory level

I want to calculate the vertical excitation energy using the DLPNO-STEOM-CCSD method, on molecules previously optimized using TD-DFT. the parameters being used are as follows: ...
Madeleine Fisher's user avatar
5 votes
0 answers
237 views

How to calculate singlet-triplet splitting energy with TD-DFT in ORCA?

I wish to reproduce the results from this paper by Truhlar and co-workers, where they treat a spin-forbidden reaction by considering two effective states coupled by a semi-empirical spin-orbit ...
S R Maiti's user avatar
  • 7,011
4 votes
0 answers
51 views

How to compute only part of molecular Hessian accurately (hybrid Hessian or partial Hessian calculation)?

Hessian is required for minimisation and transition state (TS) optimisation algorithms. While the full Hessian at a certain level of theory is calculated usually for TS optimisation, usually ...
S R Maiti's user avatar
  • 7,011
4 votes
1 answer
164 views

Question on CPU timings and/or ratio resp. DLPNO-CCSD(T) and wB97X-2-D for protein of ca. 1M Da

Suppose one has a protein of about 1 million Da, and performs a DLPNO-CCSD(T)/def2-TZVPPD/AutoAux/AutoAux calculation, and then performs a wB97X-2-D/def2-TZVPPD/AutoAux/AutoAux calculation, both via ...
Kanghun Kim's user avatar
4 votes
0 answers
202 views

orca_vpot problem

I'm trying to calculate the electrostatic potential of a molecule. When I try to use the orca_vpot tool, I am facing some difficulties detailed below. The first ...
vifontenelle's user avatar
5 votes
1 answer
652 views

Running multinode parallel Orca calculation without a work load manager (scheduler)

I wonder, if someone has run (runs) parallel Orca calculations on at least two nodes without a work load manager (scheduler)? I am asking because I have several interconnected servers (nodes) I'd like ...
EvGeniy's user avatar
  • 371
5 votes
1 answer
229 views

Does it make any sense to run a TD-DFT calculation with Finite-Temperature SCF active?

I recently received the task to investigate what is happening in a fluorescent molecule in different temperatures. How the electronic population is changing and how is this affecting the electronic ...
HCSthe2nd's user avatar
  • 327
7 votes
3 answers
3k views

Running an ORCA calculation from Python

I'm a master's student and recently I started doing computational chemistry calculations using ORCA program. This program works by command line and I saw that the majority of computational chemistry ...
Al1010's user avatar
  • 165
3 votes
1 answer
386 views

What is the difference between actual energy vs scf energy in an orca scan

Always at the end of the output of a scan type calculation in orca there are two tables one with the name "The Surface Calculated using the 'Actual Energy'" and the other "The Surface ...
Mateus Augusto's user avatar
3 votes
1 answer
407 views

Orca calculation with scan error related with auxiliary basis

I'm trying to do a SCAN calculation in the ORCA program version 5.0.3 in which, at a certain moment of the carbon-carbon bond breakage, the following error message appears: ...
Mateus Augusto's user avatar
5 votes
0 answers
175 views

ORCA failed during NEB-TS ONIOM [closed]

Thanks in advance for any help provided. I was trying to find the transition state of a diels alder reaction and considering my system's bulkiness I wanted to try a NEB calculation considering part of ...
Laura Marcon's user avatar
5 votes
3 answers
577 views

Energy of each fragment in ORCA?

After the definition of the fragments in the geometry section of the calculation, is there a method to call, or a keyword to turn on, in order to obtain the energy of the fragments themselves? ...
Andrea Pellegrini's user avatar
5 votes
1 answer
1k views

Numerical Evaluation of Hessian?

I am trying to understand the construction of Hessian matrix using numerical differentiation (NUMFREQ option in ORCA for example). I understand that Hessian is a square matrix containing second ...
Hemanth Haridas's user avatar
2 votes
0 answers
49 views

How to handle explicit solvent molecules when calculating energies of reactant molecules in isolation [closed]

When determining the energy barrier, it is recommended to compute the energies of reactant molecules in isolation to account for the entropy change of forming the reactant complex (hence factoring ...
learner254's user avatar
3 votes
1 answer
994 views

ORCA: Getting the error "mpirun noticed that process rank 0 with PID 383161 on node exited on signal 11 (Segmentation fault)."

I am getting a segmentation fault error when running the following input file below. The calculation runs fine in gas phase and CPCM modes, but fails with SMD. What could be the issue? Some are saying ...
learner254's user avatar
6 votes
1 answer
189 views

Is it possible to restrict the calculation of frequencies in ORCA program?

I looked in the orca manual but didn't find anything, but in the case of having a molecule adsorbed in a cluster, is it possible to perform the frequency calculation only on the molecule and not on ...
Mateus Augusto's user avatar
4 votes
1 answer
787 views

Optimise S1 geometry with CASSCF in ORCA

I'm trying to optimise the excited state of benzene using ORCA 5.0.1 software. I've already optimised the $S_0$ geometry with CAS-SCF[6,5] with the following input file ...
Andrea Pellegrini's user avatar
4 votes
1 answer
233 views

How does ORCA treat intermediates in Nudged Elastic Band (NEB) calculations

I'm trying to run a quite complicated NEB optimization with (hopefully) one intermediate structure. But before losing time, I was wondering: how does ORCA treat that intermediate? does ORCA optimize ...
Andrea Pellegrini's user avatar
6 votes
1 answer
590 views

Unrecognized or duplicated keyword error using ORCA DFT calculations using avogadro

I'm using Avogadro to generate an input for ORCA, however, when I'm trying to run that input in ORCA it says: ...
Hector dks's user avatar
4 votes
1 answer
356 views

How many electrons and orbitals should I include in a CASSCF calculation?

I'm interested in running CASSCF calculations to get a dissociation curve for a number of systems of the form: atom-atom, atom-diatomic or diatomic-diatomic (e.g. Li+ ... O-, K+ ... O2, or N(3-) ... ...
Alex I's user avatar
  • 1,038
5 votes
0 answers
123 views

How to scan Improper Dihedral in Orca? [closed]

I am using Orca 4.2.1 for the ab initio calculation. Scanning the redundant coordinates I am trying to scan potential surface for different type of bonds, angles and dihedrals. How can I do so for ...
Md. Rifat Hossain Kawshik's user avatar
5 votes
0 answers
81 views

Does a TD-DFT excitation from a closed-shell determinant only include the alpha electron part?

From an input in ORCA 5.0.3 ! PBE 6-31G* %TDDFT NROOTS 3 END * xyz 0 1 H 0. 0. 0. H 0. 0. 0.7414 * the output includes ...
cistrans's user avatar
4 votes
1 answer
136 views

Recalc entropy and free energy from scaled hessian

I have already performed a FREQ calculation on my system. Following the manual, I then changed the scalar factor accordingly to the theory level I've done my calculation. As procedure suggested in the ...
Andrea Pellegrini's user avatar
4 votes
0 answers
2k views

ORCA finished by error termination in SCF gradient [closed]

I try to optimize and compute frequencies for the system built up from C, O, H, and Co atoms in the following functionals: B2PLYP, B2PLYP-D3, B3LYP, B3LYP-D3, BLYP, BLYP-D3, DSD-PBEP86, PBE, PBE-D3, ...
farmaceut's user avatar
9 votes
1 answer
233 views

QuasiRRHO in Orca

I read that ORCA runs a QuasiRRHO calculation based on Grimme approximation, at the end of a freq calculation. Unfortunately, I wasn't able to find the default value for the CutOffFreq. In Grimme's ...
Andrea Pellegrini's user avatar
5 votes
1 answer
387 views

Successfully running parallel gas phase calculation on AMD cloud instance but implicit solvent fails (Local Intel workstation successfully runs both)

I am using an AMD Linux cloud-based instance to ran general optimisation and transition state calculations in parallel. I have noticed that I can run gas phase calculations in parallel but the run ...
learner254's user avatar
5 votes
2 answers
641 views

ORCA: Dipole moment of LiH from SP calculation

I calculate LiH with ORCA ...
Sergio's user avatar
  • 357
7 votes
1 answer
288 views

Simulating autoionization of small molecules using DFT or AIMD

From what I'm reading, simulation of auto-ionization in liquid substances is hard to do using gas phase DFT or AIMD [1][2][3]. I am using ORCA to do my work and I must confess that I'm shocked to see ...
HCSthe2nd's user avatar
  • 327
6 votes
2 answers
622 views

Bromine basis set problem

I'm trying to compute the energy of the benzyl bromide with orca. I need it to be at ωB97x-d4/6-31g(d) level. Orca throws me the following error. ...
Andrea Pellegrini's user avatar
5 votes
1 answer
347 views

ORCA: CIS calculation for Helium atom

I want to understand ORCA output for CIS calculations. From the input file ...
Sergio's user avatar
  • 357
6 votes
0 answers
761 views

MOLDEN file from ORCA output [closed]

I'm trying to convert an ORCA output file into MOLDEN file (via molden itself). I hit the "Write" button and it converts the file, yes, but the displacement vector s are zeros. I need that ...
Andrea Pellegrini's user avatar
4 votes
1 answer
399 views

ORCA: meaning of numbers in ORCA.out of MOLECULAR ORBITALS for STO-3G Lithium

For Lithium STO-3G basis set ...
Sergio's user avatar
  • 357
5 votes
1 answer
356 views

Non-equilibrium CPCM for Orca Absorption Spectra

I run into this article[1] in which they figure out that if you want to correctly simulate electronic spectra you have to consider the non-equilibrium solvation. I've made research into the ...
Andrea Pellegrini's user avatar