exercises:2014_ethz_mmm:basis_sets
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exercise:basis_sets [2014/03/25 13:13] – sclelia | exercise:basis_sets [2014/04/02 15:22] – [Basis Sets] oschuett | ||
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====== Basis Sets ====== | ====== Basis Sets ====== | ||
In this exericse you will compare different basis sets and use them for computing the binding energy of an H2 molecule. | In this exericse you will compare different basis sets and use them for computing the binding energy of an H2 molecule. | ||
- | The cp2k basis set format is the following: | + | The cp2k basis set format is described in detail [[:basis_sets|here]]. |
- | < | + | ===== Part I: Different |
- | + | ||
- | Nsets | + | |
- | n1 lmin lmax Nexp Ncontr | + | |
- | exp1 contr1 contr2 contr3 ... | + | |
- | exp2 contr4 contr5 contr6 ... | + | |
- | Nexp.... | + | |
- | n2 lmin lmax Nexp Ncontr | + | |
- | exp1 contr1 contr2 contr3 ... | + | |
- | exp2 contr4 contr5 contr6 ... | + | |
- | Nexp.... | + | |
- | ... | + | |
- | </ | + | |
- | \\ | + | |
- | Nsets = number of sets. \\ | + | |
- | n1,n2... = main quantum number (but it gets ignored by the program!) \\ | + | |
- | lmin = min //l// (angular quantum number) of the set ( s = 0 ; p = 1 ; d = 2 ...) \\ | + | |
- | lmax = max //l// (angular quantum number) of the set ( s = 0 ; p = 1 ; d = 2 ...) \\ | + | |
- | Nexp = number of exponents of the set \\ | + | |
- | Ncontr = number of contaction coefficients per angular quantum number \\ | + | |
- | + | ||
- | As an example: | + | |
- | + | ||
- | < | + | |
- | 2 2 Sets | + | |
- | 1 0 0 1 1 Set 1: lmin=0 ; lmax=0 (→ s functions!) ; 1 exponent ; 1 contraction | + | |
- | 0.35 1 exponent1 of set 1 ; contraction | + | |
- | 1 1 1 1 1 Set 2: lmin=1 ; lmax=1 (→ p functions!) ; 1 exponenet ; 1 contraction | + | |
- | 0.6 1 | + | |
- | </ | + | |
- | + | ||
- | + | ||
- | ===== Part I: Create your own basis set for H ===== | + | |
==== 1.Step ==== | ==== 1.Step ==== | ||
- | Save the following input file. Comment lines are marked with ! | + | Run a calculation with the following input file. Comment lines are marked with ! |
<code - mybasis.inp > | <code - mybasis.inp > | ||
+ | |||
&GLOBAL | &GLOBAL | ||
PROJECT H-mybasis | PROJECT H-mybasis | ||
Line 48: | Line 18: | ||
& | & | ||
- | METHOD Quickstep | + | METHOD Quickstep |
+ | | ||
&DFT | &DFT | ||
- | POTENTIAL_FILE_NAME ./ | + | LSD |
- | LSD | + | |
- | & | + | & |
- | CUTOFF 200 | + | PERIODIC NONE |
- | &END MGRID | + | PSOLVER |
- | & | + | & |
- | PERIODIC NONE | + | & |
- | PSOLVER | + | METHOD GAPW ! Method: gaussian and augmented plane waves |
- | &END | + | |
- | &QS | + | |
- | METHOD GAPW | + | |
&END QS | &END QS | ||
- | | + | & |
- | EPS_SCF 1.0E-6 | + | & |
- | SCF_GUESS ATOMIC | + | |
- | &END SCF | + | |
- | | + | |
- | & | + | |
&END XC_FUNCTIONAL | &END XC_FUNCTIONAL | ||
- | &HF | + | & |
- | & | + | & |
- | EPS_SCHWARZ 1.0E-10 | + | EPS_SCHWARZ 1.0E-10 |
- | &END | + | & |
- | & | + | & |
- | MAX_MEMORY | + | |
- | &END | + | |
- | &END | + | |
&END XC | &END XC | ||
&END DFT | &END DFT | ||
+ | | ||
&SUBSYS | &SUBSYS | ||
+ | & | ||
+ | & | ||
+ | &END | ||
+ | &END | ||
&CELL | &CELL | ||
ABC 10.0 10.0 10.0 | ABC 10.0 10.0 10.0 | ||
- | PERIODIC NONE | + | PERIODIC NONE ! Non periodic calculations. That's why the POISSON scetion is needed |
&END CELL | &END CELL | ||
&COORD | &COORD | ||
- | | + | |
&END COORD | &END COORD | ||
&KIND H | &KIND H | ||
- | & | + | & |
2 | 2 | ||
1 0 0 1 1 | 1 0 0 1 1 | ||
Line 95: | Line 61: | ||
0.6 1 | 0.6 1 | ||
& | & | ||
- | | + | |
+ | & | ||
+ | | ||
+ | | ||
+ | & | ||
&END KIND | &END KIND | ||
&END SUBSYS | &END SUBSYS | ||
&END FORCE_EVAL | &END FORCE_EVAL | ||
+ | </ | ||
+ | ==== 2.Step ==== | ||
+ | Try to change the basis set, and report the obtained energy values for H. | ||
+ | After a couple of tries on your own, try to use some of the literature basis sets (given at the end of this exercise). | ||
+ | At the end, you should get a table like this : | ||
+ | |||
+ | |||
+ | ^ Basis set ^ Energy | ||
+ | | mybasis (from given input) | ||
+ | | basis try 1 | .... | | ||
+ | | basis try 2 | .... | | ||
+ | | .... | .... | | ||
+ | | pc-0 | .... | | ||
+ | | pc-1 | .... | | ||
+ | | pc-2 | .... | | ||
+ | |||
+ | <note tip>Is always good to keep record of self-created basis sets, to track the effect of a change in value and number of exponents, contractions....etc.. </ | ||
+ | |||
+ | Repeat the procedure for H2. \\ | ||
+ | H2 coordinates: | ||
+ | < | ||
+ | H 0 0 0 | ||
+ | H 0.75 0 0 | ||
</ | </ | ||
+ | |||
+ | <note important> | ||
+ | |||
+ | ===== Part II: Estimate the binding energy of H2 ===== | ||
+ | |||
+ | Binding energy: \\ | ||
+ | |||
+ | \[ \sum E_\text{products} - \sum E_\text{rectants} = E(H_2) - 2 \cdot E(H) \] | ||
+ | |||
+ | <note important> | ||
+ | |||
+ | |||
+ | You can now update your table: | ||
+ | |||
+ | ^ Basis set ^ Energy | ||
+ | | mybasis (from given input) | ||
+ | | basis try 1 | .... | .... | .... | | ||
+ | | basis try 2 | .... | .... | .... | | ||
+ | | .... | .... | .... | .... | | ||
+ | | pc-0 | .... | .... | .... | | ||
+ | | pc-1 | .... | .... | .... | | ||
+ | | pc-2 | .... | .... | .... | | ||
+ | | .... | .... | .... | .... | | ||
+ | |||
+ | ===== Part III: Questions ===== | ||
+ | |||
+ | - What is the effect of:\\ | ||
+ | * increasing/ | ||
+ | * adding sets with p,d symmetry to the basis? You have the same effect in H and H2? | ||
+ | |||
+ | |||
+ | ===== Part IV: Additional basis sets ===== | ||
+ | |||
+ | |||
+ | |||
+ | H pc-0 | ||
+ | 2 | ||
+ | 1 0 0 2 1 | ||
+ | 4.34480000 | ||
+ | 0.66049000 | ||
+ | 1 0 0 1 1 | ||
+ | 0.13669000 | ||
+ | |||
+ | H pc-1 | ||
+ | 3 | ||
+ | 1 0 0 3 1 | ||
+ | | ||
+ | 1.86870000 | ||
+ | 0.41821000 | ||
+ | 1 0 0 1 1 | ||
+ | 0.10610000 | ||
+ | 1 1 1 1 1 | ||
+ | 1.00000000 | ||
+ | |||
+ | H pc-2 | ||
+ | 6 | ||
+ | 1 0 0 4 1 | ||
+ | | ||
+ | | ||
+ | 2.59930000 | ||
+ | 0.73513000 | ||
+ | 1 0 0 1 1 | ||
+ | 0.23167000 | ||
+ | 1 0 0 1 1 | ||
+ | 0.07414700 | ||
+ | 1 1 1 1 1 | ||
+ | 1.60000000 | ||
+ | 1 1 1 1 1 | ||
+ | 0.45000000 | ||
+ | 1 2 2 1 1 | ||
+ | 1.25000000 | ||
+ | |||
+ | |||
+ | |||
+ | |||
+ |
exercises/2014_ethz_mmm/basis_sets.txt · Last modified: 2020/08/21 10:15 by 127.0.0.1