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exercise:basis_sets [2014/03/26 15:00] – [1.Step] scleliaexercise:basis_sets [2014/04/02 15:22] – [Basis Sets] oschuett
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 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]].
- +
-<code> +
- +
-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.... +
-    ... +
-</code> +
-\\ +
-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: +
- +
-<code> +
-      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           exponent1 of set 2 ;  contraction +
-</code> +
  
 ===== Part I: Different basis sets for H and H2 ===== ===== Part I: Different basis sets for H and H2 =====
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   &SUBSYS   &SUBSYS
 +    &TOPOLOGY                              ! Section used to center the molecule in the simulation box. Useful for big molecules 
 +      &CENTER_COORDINATES                  
 +      &END
 +    &END
     &CELL     &CELL
       ABC 10.0 10.0 10.0       ABC 10.0 10.0 10.0
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      &END      &END
      POTENTIAL ALL                         ! Specifes that the potential is for all electron calculations.      POTENTIAL ALL                         ! Specifes that the potential is for all electron calculations.
-     &POTENTIAL                            ! Usual all eletcron potential for H +     &POTENTIAL                            ! Usual all electron potential for H 
         0    0         0    0
      0.20000000    0      0.20000000    0
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 <code> <code>
 H 0 0 0      H 0 0 0     
-H 0.0 0   +H 0.75 0 0   
 </code> </code>
  
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 Binding energy: \\  Binding energy: \\ 
-{{ :exercise:ppp.jpg?300 |}} 
  
 +\[ \sum E_\text{products} -  \sum E_\text{rectants} = E(H_2) - 2 \cdot E(H) \]
  
 <note important> The binding energy value is significant only if the same basis is used for both reactants and products. </note> <note important> The binding energy value is significant only if the same basis is used for both reactants and products. </note>
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 ===== Part III: Questions ===== ===== Part III: Questions =====
  
-1.1- Report two self-made basis sets and the corresponding H energy.  +- What is the effect of:\\
- +
-1.2- What is the effect of:\\+
   * increasing/decreasing the value of the exponents for the given basis?   * increasing/decreasing the value of the exponents for the given basis?
   * adding sets with p,d symmetry to the basis? You have the same effect in H and H2?   * adding sets with p,d symmetry to the basis? You have the same effect in H and H2?
exercises/2014_ethz_mmm/basis_sets.txt · Last modified: 2020/08/21 10:15 by 127.0.0.1