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basis_sets [2014/03/31 13:22] oschuettbasis_sets [2020/08/21 10:15] – external edit 127.0.0.1
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 Where $R(r)$ denotes the radial part and $Y_{lm}(\theta, \phi)$ [[wp>Spherical_harmonics|spherical harmonics]] for the angular part. From a physical point of view the best choice for the radial part would be [[wp>Slater-type_orbital|Slater-type orbitals]]. However, CP2K uses contracted Gaussians instead, because they have nicer analytic properties. Contracted Gaussians are simply a weighted sum of primitive Gaussians with different exponents: Where $R(r)$ denotes the radial part and $Y_{lm}(\theta, \phi)$ [[wp>Spherical_harmonics|spherical harmonics]] for the angular part. From a physical point of view the best choice for the radial part would be [[wp>Slater-type_orbital|Slater-type orbitals]]. However, CP2K uses contracted Gaussians instead, because they have nicer analytic properties. Contracted Gaussians are simply a weighted sum of primitive Gaussians with different exponents:
-\[ R_i(r) = \sum_{j=1}^N c_{ij}\cdot \exp(\alpha_j\cdot r^2) \]+\[ R_i(r) = r^{l_i} \sum_{j=1}^N c_{ij}\cdot \exp(-\alpha_j\cdot r^2) \]
  
 ===== File Format ===== ===== File Format =====
  
-We explain the file-format using the following example from the file ''$CP2K_HOME/tests/QS/BASIS_SET'':+We explain the file-format using the following example from the file ''$CP2K_HOME/data/BASIS_SET'':
 <code> <code>
    # Silicon    # Silicon
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   * The fourth number specifies the number of exponents (here: 4).   * The fourth number specifies the number of exponents (here: 4).
  
-The following number specify the number of contractions for each angular momentum value $M$.  +The following numbers specify the number of contracted basis functions for each angular momentum value.  
-  * The fifth number specifies the number of contractions for $l=0$ or s-functions (here: $M_s=2$). +  * The fifth number specifies the number of contractions for $l=0$ or s-functions (here: 2). 
-  * The sixth number specifies the number of contractions for $l=1$ or p-functions (here: $M_p=2$).+  * The sixth number specifies the number of contractions for $l=1$ or p-functions (here: 2).
  
 **Line 10-13** specify the coefficients of the first set. **Line 10-13** specify the coefficients of the first set.
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 \begin{align} \begin{align}
  
-\varphi_1(\vec r) & Y_{0,\ 0}\left [0.321 \cdot e^{1.181r^2}  -0.245 \cdot e^{0.445r^2} -0.795 \cdot e^{0.164r^2} - 0.182 \cdot e^{0.056 r^2} \right ] \\+\varphi_1(\vec r) & Y_{0,\ 0}\left [0.321 \cdot e^{-1.181r^2}  -0.245 \cdot e^{-0.445r^2} -0.795 \cdot e^{-0.164r^2} - 0.182 \cdot e^{-0.056 r^2} \right ] \\
  
-\varphi_2(\vec r) & Y_{0,0} \cdot e^{0.056 r^2} \\+\varphi_2(\vec r) & Y_{0,0} \cdot e^{-0.056 r^2} \\
  
-\varphi_3(\vec r) & Y_{1,-1}\left [0.046 \cdot e^{1.181r^2}  -0.263 \cdot e^{0.445r^2} -0.543 \cdot e^{0.164r^2} - 0.543 \cdot e^{0.056 r^2} \right ] \\+\varphi_3(\vec r) & Y_{1,-1}\cdot r \left [0.046 \cdot e^{-1.181r^2}  -0.263 \cdot e^{-0.445r^2} -0.543 \cdot e^{-0.164r^2} - 0.356 \cdot e^{-0.056 r^2} \right ] \\
  
-\varphi_4(\vec r) & Y_{1,0}\left [0.046 \cdot e^{1.181r^2}  -0.263 \cdot e^{0.445r^2} -0.543 \cdot e^{0.164r^2} - 0.543 \cdot e^{0.056 r^2} \right ] \\+\varphi_4(\vec r) & Y_{1,0}\cdot r \left [0.046 \cdot e^{-1.181r^2}  -0.263 \cdot e^{-0.445r^2} -0.543 \cdot e^{-0.164r^2} - 0.356 \cdot e^{-0.056 r^2} \right ] \\
  
-\varphi_5(\vec r) & Y_{1, +1}\left [0.046 \cdot e^{1.181r^2}  -0.263 \cdot e^{0.445r^2} -0.543 \cdot e^{0.164r^2} - 0.543 \cdot e^{0.056 r^2} \right ] \\+\varphi_5(\vec r) & Y_{1, +1}\cdot r \left [0.046 \cdot e^{-1.181r^2}  -0.263 \cdot e^{-0.445r^2} -0.543 \cdot e^{-0.164r^2} - 0.356 \cdot e^{-0.056 r^2} \right ] \\
  
-\varphi_6(\vec r) & Y_{1,-1} \cdot e^{0.056 r^2} \\+\varphi_6(\vec r) & Y_{1,-1} \cdot r \cdot e^{-0.056 r^2} \\
  
-\varphi_7(\vec r) & Y_{1,0} \cdot e^{0.056 r^2}  \\+\varphi_7(\vec r) & Y_{1,0} \cdot r \cdot e^{-0.056 r^2}  \\
  
-\varphi_8(\vec r) & Y_{1, +1} \cdot e^{0.056 r^2}+\varphi_8(\vec r) & Y_{1, +1} \cdot r \cdot e^{-0.056 r^2}
  
 \end{align} \end{align}
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 \begin{align} \begin{align}
-\varphi_9(\vec r) & Y_{2,-2} \cdot e^{0.45 r^2}  \\ +\varphi_9(\vec r) & Y_{2,-2} \cdot r^2 \cdot e^{-0.45 r^2}  \\ 
-\varphi_{10}(\vec r) & Y_{2,-1} \cdot e^{0.45 r^2}  \\ +\varphi_{10}(\vec r) & Y_{2,-1} \cdot r^2 \cdot e^{-0.45 r^2}  \\ 
-\varphi_{11}(\vec r) & Y_{2,0} \cdot e^{0.45 r^2}  \\ +\varphi_{11}(\vec r) & Y_{2,0} \cdot r^2 \cdot e^{-0.45 r^2}  \\ 
-\varphi_{12}(\vec r) & Y_{2, +1} \cdot e^{0.45 r^2}  \\ +\varphi_{12}(\vec r) & Y_{2, +1} \cdot r^2 \cdot e^{-0.45 r^2}  \\ 
-\varphi_{13}(\vec r) & Y_{2, +2} \cdot e^{0.45 r^2} +\varphi_{13}(\vec r) & Y_{2, +2} \cdot r^2 \cdot e^{-0.45 r^2} 
 \end{align} \end{align}
  
basis_sets.txt · Last modified: 2020/11/07 12:57 by oschuett