Difference between revisions of "Solution LAB2 guanine 3"
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Also, the following option needs to be used for charged systems : | Also, the following option needs to be used for charged systems : | ||
assume_isolated="mt" | assume_isolated="mt" | ||
+ | |||
+ | Using ecutwfc=50 Ry and 35 au of cell size, | ||
+ | E_tot(N) = | ||
+ | E_tot(N-1) = -192.89782124 Ry | ||
+ | |||
+ | giving | ||
+ | |||
+ | Interestingly, one can run the same set of calculations also using different functionals, | ||
+ | including GGAs (PBE), meta-GGAs (eg TPSS or SCAN), hybrids (PBE0), or HF itself. | ||
+ | |||
+ | In order to do this, you can force e.g. the functional from input, by using: | ||
+ | |||
+ | &SYSTEM | ||
+ | [...] | ||
+ | input_dft="PBE0" | ||
+ | / | ||
+ | |||
+ | How do -eps_HOMO and delta-scf values compare ? |
Revision as of 12:33, 26 March 2021
- Back to the previous page: Electronic properties of isolated molecules#Exercise 3
For calculation of E(N-1) we need to set the following flags in the &SYSTEM namelist:
nspin=2 ! Note, now we have unpaired electrons: tot_charge=+1 ! charged system tot_magnetization=1 ! we need to set a total magnetisation
Also, the following option needs to be used for charged systems :
assume_isolated="mt"
Using ecutwfc=50 Ry and 35 au of cell size,
E_tot(N) = E_tot(N-1) = -192.89782124 Ry
giving
Interestingly, one can run the same set of calculations also using different functionals, including GGAs (PBE), meta-GGAs (eg TPSS or SCAN), hybrids (PBE0), or HF itself.
In order to do this, you can force e.g. the functional from input, by using:
&SYSTEM [...] input_dft="PBE0" /
How do -eps_HOMO and delta-scf values compare ?