Keshav Singh

12 Questions 27 Answers 0 Followers

Questions related from Keshav Singh

How to solve error "basis set is linearly dependent" ?

I am trying to optimize a molecular crystal using CRYSTAL17 software. I am getting error that the basis set I am using is linearly dependent. How can I solve such issue. I tried changing my basis...

09 March 2022 6,939 6 View

Problem in running USPEX with LAMMPS for Crystal Structure Prediction?

I am trying to run USPEX with LAMMPS (example 4, in USPEX examples). However, when I try to run USPEX, I always get following error lmp_stable:...

24 August 2021 3,888 1 View

How to generate a structure of metal nanocluster using either quantum espresso or LAMMPS?

I am new to the quantum espresso and LAMMPS program. I wish to make nanocluster of Bismuth. Is it possible generate a structure of Bismuth nanocluster using either quantum espresso or LAMMPS? If...

11 August 2021 9,407 7 View

How to extract Fractional coordinates form the cif file?

I am new to the solid state ab-initio calculations. I need to optimize the unit cell of paracetamol. For this, I required Fractional coordinates for the system. When I extract fractional...

22 March 2021 7,335 2 View

Why it is required to optimize a unit cell generated from cif lattice parameters and atomic coordinates during ab initio solid state calculations?

A cif file represents a unit cell with minimum energy. My question is, in the start of any ab initio calculation for unit cell generated from the cif file, why we are advised to optimize cell...

20 January 2021 10,080 3 View

How to calculate IR and RAMAN spectra form Born charge ?

I am using crystal 17 for my solid state ab initio calculations. For some reason the program is not able to produce the Raman spectra but have generated born charges. Is there any way to produce...

12 January 2021 2,462 2 View

Can someone help me with the error in crystal17 output ?

I am a new user to crystal 17 (https://www.crystal.unito.it/index.php). I was trying to optimize a molecule using crystal17 but it is throwing following error: "ERROR **** INPUT3 **** n-D...

20 October 2020 5,400 2 View

Can you suggest any book to learn material simulation via density functional theory?

I am new to material simulation and I am willing to learn the theoretical aspects like what is k point mesh, how to interpret band diagram, how born charge results in IR spectra etc. I have...

30 August 2020 1,319 8 View

What are the criteria to say any system of molecules a "pre-reaction complex"

I am working of a reaction CH2 + CH2NH  CH3CHNH. Before reacting those molecules I should form pre-reaction complex to have proper reference of energy to calculate barrier to the reaction (energy...

08 September 2016 2,540 3 View

What is the difference between doing single point calculations in PCM model at optmized gas phase geometry and reperforming reaction in pcm model?

I am working on the reaction mechanism for pre-biotic molecules in amorphous interstellar ice. I have performed a reaction (ch2+ch2nh-->ch3chnh) both in gas phase and also with four water...

23 June 2016 750 9 View

What is the correct way to form reaction complex(RC)?

I am trying to react CH2 (singlet) and CH2NH to form CH3CHNH. I form RC by placing the reactants at sum of the Vanderwall radius of the carbon atoms(1.7 angstrom for carbon) of CH2 and CH2NH as...

12 May 2016 4,418 1 View

When dealing with open shell system like Methylene (ch2) which is the batter choice, MP2 method or a double hybrid dft functional like b2plyp?

I am working on a reaction in which there is a step involving the reaction between ch3 and ch2 . I have done this with wb97xd/6-311+g(d,p). now I want to repeat the same reaction which involves...

01 January 1970 5,234 3 View