At and mol further: Difference between revisions

Revision as of 19:26, 22 June 2019

Overview > O atom > O atom spinpolarized > O atom spinpolarized low symmetry > O dimer > CO > CO vibration > CO partial DOS > H2O > H2O vibration > H2O molecular dynamics > Further things to try > List of tutorials

How does the energy change when one decreases SIGMA to 0.001 in the INCAR file starting from the [[O_atom? Why?

Try to copy CONTCAR to POSCAR after running the example O_dimer. Why is the calculation so fast?

Try to play with the parameter POTIM for the example O_dimer. What is the optimal value?

What is the reason for the imaginary frequency in the example CO_vibration? Does the behaviour improve when the step width (smaller or larger) is changed? Also try to improve the precision to which the ground state is converged (EDIFF=1E-5). What happens if the accuracy of the calculations is improved (PREC=Accurate).

Try to use the conjugate gradient algorithm to the $\mathrm{H}_{2}\mathrm{O}$ molecule (example H2O).

Calculate the vibrational frequencies of the $\mathrm{H}_{2}\mathrm{O}$ molecule (example H2O) after relaxation (example H2O vibration). Why does one find 3 modes that have small frequencies? Try EDIFF=1E-5 instead of EDIFF=1E-4.

Overview > O atom > O atom spinpolarized > O atom spinpolarized low symmetry > O dimer > CO > CO vibration > CO partial DOS > H2O > H2O vibration > H2O molecular dynamics > Further things to try > List of tutorials

Back to the main page.

@@ Line 1: / Line 1: @@
 {{Template:At_and_mol - Tutorial}}
-*How does the energy change when one decreases {{TAG|SIGMA}} to 0.001 in the {{TAG|INCAR}} file starting from the {{TAG|O_atom}}? Why?
+*How does the energy change when one decreases {{TAG|SIGMA}} to 0.001 in the {{TAG|INCAR}} file starting from the [[O_atom? Why?
-*Try to copy {{TAG|CONTCAR}} to {{TAG|POSCAR}} after running the example {{TAG|O_dimer}}. Why is the calculation so fast?
+*Try to copy {{FILE|CONTCAR}} to {{FILE|POSCAR}} after running the example {{TAG|O_dimer}}. Why is the calculation so fast?
 *Try to play with the parameter {{TAG|POTIM}} for the example {{TAG|O_dimer}}. What is the optimal value?
-*What is the reason for the imaginary frequency in the example {{TAG|CO_vibration}}? Does the behaviour improve when the step width (smaller or larger) is changed? Also try to improve the precision to which the ground state is converged ({{TAG|EDIFF}}=1E-5). What happens if the accuracy of the calculations is improved ({{TAG|PREC}}=''Accurate''}}).
+*What is the reason for the imaginary frequency in the example {{TAG|CO_vibration}}? Does the behaviour improve when the step width (smaller or larger) is changed? Also try to improve the precision to which the ground state is converged ({{TAG|EDIFF}}=1E-5). What happens if the accuracy of the calculations is improved ({{TAG|PREC}}=''Accurate'').
-*Try to use the conjugate gradient algorithm to the <math>\mathrm{H}_{2}\mathrm{O}</math> molecule (example {{TAG|H2O}}).
+*Try to use the conjugate gradient algorithm to the <math>\mathrm{H}_{2}\mathrm{O}</math> molecule (example [[H2O]]).
-*Calculate the vibrational frequencies of the <math>\mathrm{H}_{2}\mathrm{O}</math> molecule (example {{TAG|H2O}}) after relaxation (example {{TAG|H2Ovib}}). Why does one find 3 modes that have small frequencies? Try {{TAG|EDIFF}}=1E-5 instead of {{TAG|EDIFF}}=1E-4.
+*Calculate the vibrational frequencies of the <math>\mathrm{H}_{2}\mathrm{O}</math> molecule (example [[H2O]]) after relaxation (example [[H2O vibration]]). Why does one find 3 modes that have small frequencies? Try {{TAG|EDIFF}}=1E-5 instead of {{TAG|EDIFF}}=1E-4.