UT theoretical chemistry code forum

Thanks for clarification and good news I tried to reduce the residual forces to less than 0.1 eV/A as below (attached) 0 0.000000 -200.036100 0.000000 1 0.009956 -198.167800 1.868300 2 0.041363 -198.085300 1.950800 3 0.095117 -197.881700 2.154400 4 0.089032 -196.932200 3.103900 5 0.091099 -197.22830...

Thank you very much for your answer and patience. I attached the initial cNEB calculation here.results are shown in Results subfolder. I came across http://theory.cm.utexas.edu/forum/viewtopic.php?f=2&t=3252&p=9530&hilit=dimer+trouble#p9530 it seems he faced the same problem too. As per ...

Dear Prof.Graeme, Updating our previous discussion,I have tried to ensure final configuration for these gas dissociation reaction. H2: While it worked for H2 dissociation H2-->H*+H* with 0.16eV in agreement with literature expectation ,I could not confirm the transition state by either dynamic matri...

Dear Dr.Graeme,

Thanks for your reply and share those two similar examples.One main idea-as you said- I got is that my final states are not stable on surface ((although they are converged).I will try fix that to see how it will work.

Thanks

Hi Dr.Graeme Yes,as you expected it is gas dissociation.Specifically ,I am facing the problem with H2,CH4 and CO2 which are physically adsorbed with week adsorption energies(-0.02 to -0.06 eV).The two main problems -as you mentioned- are either I got is either jump between image (+2eV) or high force...

Dear Dr.Graeme, I am T.S. for different elementary reaction on Ni (111) .While most of calculation are going well and confirmed with one imaginary vibration,those of weakly bound molecules (namely CH4 and CO2) are not going well . CH4: After 150 iteration using QM: 0 0.000000 -200.038300 0.000000 1 ...

Hi, For dimer continuous run,In addition to vfin.pl run2 files,Can I use CHGCAR ,WAVECAR from previous run with ISTART=1 ,ICHARG=1 as per regular VASP run? In that case ,the system will use CENTCAR or CONTCAR? Can I do the same with cNEB (i.e gunzip all WAVECAR ,CHGCAR in images after using vfin.pl,...

Extending my gratitude for your help, I could manage to get convergence with Ediff=1e-4 (in this particular case below)with energy barrier 1.41 as you expected .I guess probably it worked as the convergence has already been close with the residual force 0.02 eV (ediffg=0.01). For other Dimer calcula...

Hi,Thanks for your patience and explanation. Here is result when I switch again DImer after 150 cNEB iterations Step Force Torque Energy Curvature Angle 1 0.84923 3.62994 -185.70560 -2.23269 18.47678 2 0.96178 2.76292 -185.70971 -3.97754 17.11630 3 1.13131 3.61388 -185.74328 -6.45217 11.62957 4 1.40...

Thank you for your support. Yes,I have used neb2dim.pl as follow:From NEB directory I make 1)vfin.pl Results 2)~>Results/nebresults.pl 3)~>Results/neb2dim.pl .The last step created "dim" folder with (INCAR KPOINTS MODECAR POSCAR POTCAR) which I used for the next run. I have already continu...

Hi I stil face some problems when switching from QM optimizer to Dimer.For instance,I check of CH dissociation on catalyst and I got the following results from 8 images using nebef.dat:After 50 iterations,I got 0 0.000000 -187.570500 0.000000 1 0.056474 -187.526100 0.044400 2 0.129705 -187.352300 0....

Thank you Dr.Graeme for your valuable support

Hi, I am trying to find T.S. for CH+H on Ni-Cu catalyst.I have a some of questions. 1-I have run cNEB for NSW=50 for two time (using vfin.pl for continuous run) ,then use neb2dim.pl to utilize dimer method for NSW=100.Still calculation did not converge and wavefunction have been written after iterat...