CP2K Open Source Molecular Dynamics

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howto:rtp_field_xas [2023/10/11 10:04] – [CP2K input] glebretonhowto:rtp_field_xas [2023/10/16 16:15] – oschuett
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 In this tutorial, we will present a simulation of resonant X-Ray excitation of an isolated carbon monoxide in real-time using a time-dependent field.  In this tutorial, we will present a simulation of resonant X-Ray excitation of an isolated carbon monoxide in real-time using a time-dependent field. 
 On this page, you will find an overview of the method, some equations, and the CP2K input file.  On this page, you will find an overview of the method, some equations, and the CP2K input file. 
-A longer version is available in the form of a jupyter notebook file in {{:howto:rtp_field_xas.zip | this zip file}} along with the simulated data so that you do not need to run this calculation yourself to perform the analysis.+A longer version is available in the form of a jupyter notebook file in {{ :howto:rtp_field_xas.zip | this zip file}} along with the simulated data so that you do not need to run this calculation yourself to perform the analysis.
 This kind of calculation is not easy to grasp: do not hesitate to have a first look before diving into the equations and details!  This kind of calculation is not easy to grasp: do not hesitate to have a first look before diving into the equations and details! 
 This tutorial is connected to this article REF where you can find complementary information.  This tutorial is connected to this article REF where you can find complementary information. 
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 Where $c_\omega^a$ is the $a^{\text{th}}$ atomic coefficient of the excited state found in the XAS_TDP module. Where $c_\omega^a$ is the $a^{\text{th}}$ atomic coefficient of the excited state found in the XAS_TDP module.
-There will thus be 7 projections per time step in this case. The excited state population associated to this state is:+There will be 7 projections per time step in this case: one for each time-dependent MO. The excited state population associated with this excited state is:
  
 $$ $$
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 $$ $$
  
-The carbon monoxide molecule has a rotational symmetry along its CO bond: if one notes this axis $z$, then the $x$ and $y$-axis are equivalent by symmetry. It happens that the first available excited state for the Oxygen 1s is degenerate: there are two available states orthogonal in the $xy$-plane.  That is why ta third projection is requested: it uses the other excited state proposed by the XAD_TDP module which has the exact same frequency as the first one. +The carbon monoxide molecule has a rotational symmetry along its CO bond. If one notes this axis $z$, then the $x$ and $y$-axis are equivalent by symmetry. It happens that the first available excited state for the Oxygen 1s is degenerate: there are two available excited states orthogonal in the $xy$-plane.  That is why a third projection is requested which uses the other excited state proposed by the XAD_TDP module.
  
-Therefore, the excited state should be understood as the some over these two frequency equivalent state: +Therefore, the excited state should be understood as the sum over the two equivalent excited states:
  
 $$ $$
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 $$ $$
  
-Where $\omega'$ stands for the other equivalent excited state. +Where $\omega'$ stands for the other equivalent excited state, with $\omega=\omega'=529$ ev. 
  
  
howto/rtp_field_xas.txt · Last modified: 2024/02/24 10:02 by oschuett