In DFT or HF, is it more expensive to calculate the H matrix or to diagonalize it?

I was wondering: in common DFT (or Hartree-Fock) algorithms/codes, and in particular in solving the Roothan equation, what is the most computationally expensive part: 1- evaluate all the terms of...

01 February 2021 396 2 View

Warning in Lavaan, variance-covariance not positive definite!, model is not identified?

Dear colleagues, I am new to R, I have been using Amos for conducting CFA but came to learn that when dealing with Likert scale, Lavaan in R is a better tool to do such analysis. I started using...

30 December 2020 5,608 3 View

How can i figure out whether nanoparticles in my synthesis crosslinked or not?

i prepare protein nanoparticles. in one of my synthesis i use trifle amount of crosslinker and the nanoparticles stick in the bottom of plate. how can i understand that nanoparticles become...

03 December 2020 559 8 View

What is the best solver in OpenFOAM to study melt-water interaction?

During a severe accident in a nuclear reactor an energetic molten fuel/coolant interaction could happen, where a multiphase flow of a steam-water mixture in a region which contain drops of a...

29 November 2020 8,376 2 View

How can we define columns in 3D PLAXIS model for buildings existing near the excavation?

I started by a model using 3D PLAXIS to study the effect of deep excavations on existing buildings. The building was simulated as a surface plate with a surface load. Now I'm trying to do it as a...

29 November 2020 3,198 4 View

How to read forces from a file and apply them to a specified nodes in ANSYS APDL?

I want to apply different forces for every node. These force values are saved in .txt or .csv file. Can anybody help me to do that using APDL command. I attached Ansys input file for my model and...

15 November 2020 2,883 1 View

Where can I find off targets for Apis mellifera?

I would like to find off target sites for my sgRNA, however the more commonly used off target finders do not include apis meliifera, is there an application or website that would allow me to do...

09 November 2020 3,463 1 View

What is the best method to sterilize hydroxyapatite nanoparticles?

Powder insoluble

08 November 2020 509 3 View

Wrong cell dimension (cosAB)?

All input files with bravais lattice that contains an angle doesnt run in my Quantum espresso. i even tried running them in my friends laptop but the crash file displays the same problem. i hope...

03 November 2020 2,722 1 View

How Abaqus can generate lumped mass matrix with non zero values only at the diagonal ?

Hi everybody I generated mass matrix by Abaqus, but it has nonzero off diagonal values. I need to get lumped mass matrix with nonzero values only at the diagonal. In Ansys I can turn Lump on...

28 October 2020 5,960 4 View

error in running a model in Abaqus

Excessive rotation of nodes in node set ErrNodeExcessRotation-Step1

17 August 2021 0 0 View

error in modelling model in Abaqus

Excessive rotation of nodes in node set ErrNodeExcessRotation-Step1

17 August 2021 0 0 View

MGL tools

20 June 2021 0 0 View

i have some problem with chtMultiRegionSimpleFoam

--> FOAM FATAL ERROR: Maximum number of iterations exceeded From function Foam::scalar Foam::species::thermo::T(Foam::scalar, Foam::scalar, Foam::scalar, Foam::scalar (Foam::species::thermo::*)(Foam::scalar, Foam::scalar) const, Foam::scalar (Foam::species::thermo::*)(Foam::scalar, Foam::scalar) const, Foam::scalar (Foam::species::thermo::*)(Foam::scalar) const) const [with Thermo = Foam::hConstThermo >; Type = Foam::sensibleEnthalpy; Foam::scalar = double; Foam::species::thermo = Foam::species::thermo >, Foam::sensibleEnthalpy>] in file /home/ubuntu/OpenFOAM/OpenFOAM-4.1/src/thermophysicalModels/specie/lnInclude/thermoI.H at line 66. FOAM aborting #0 Foam::error::printStack(Foam::Ostream&) at ??:? #1 Foam::error::abort() at ??:? #2 Foam::heRhoThermo >, Foam::sensibleEnthalpy> > > >::calculate() at ??:? #3 Foam::heRhoThermo >, Foam::sensibleEnthalpy> > > >::correct() at ??:? #4 ? at ??:? #5 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6" #6 ? at ??:?

24 March 2021 0 0 View

Hello fellow researcher .. What is the meaning of your name?

I would like to create a small guide containing the meanings of the names .. Thanks to everyone who cooperates with me in achieving it.

03 March 2021 5,266 4 View

What's the best way to measure growth rates in House sparrow chicks from day 2 to day 10?

What's the best way to measure growth rates in House sparrow chicks from day 2 to day 10? Since, the growth curve from day 2 to 10 won't be like the "Logistic curve" it might not follow logistic...

03 March 2021 1,401 3 View

What test should i use in comparing the correlation between categorical and continuous variables?

Dear all, I have the variable (Surgery duration) represented by values in minutes and the variable (preoperative neuropraxia cases) represented as (Yes/No) values. I want to compare these two...

03 March 2021 5,427 5 View

What is the production process of CaFe ferroalloys?

I looking for ferro calcium production process

03 March 2021 1,755 4 View

Resistor definition in Piezoelectric bimorph with ANSYS workbench

Hello, good day! I am trying to simulate similar bimorph piezoelectric harvester with below commands. However, the output power doesn't change with resistor value. Please help to find the reason. ET,10,CIRCU94,0 !SET UP RESISTOR R,1,100000 !RESISTANCE VALUE TYPE,10 !SET ELEMENT TYPE E,1,2 !CREATE RESISTOR BETWEEN NODES 1 AND 2 Thanks in advance Regards,

02 March 2021 0 0 View

Do you know any MR image dataset?

I would like to research on MR images (0.5T and 3T). Can you please suggest some websites that I can download dataset including both 0.5T and 3T MR images? Thank you.

02 March 2021 7,735 3 View