Workshop
The Coupled Cluster Doubles Truncation Variety
- Elke Neuhaus
Abstract
The quantum states arise from the cluster amplitudes via the exponential parametrization, given by the first column of the exponential of a lower triangular matrix T, representing the cluster operator. The coordinates of the cluster amplitudes describe the probability of different electrons leaving the reference state and can therefore be categorized into different levels, based on the number of moved electrons. For the sake of simplifying the electronic Schrödinger equation, one truncates the eigenvalue problem to only allow cluster amplitudes truncated to different levels. The quantum states arising in this way belong to the so-called truncation variety. We study this zero-set and its generators in small cases for truncation at level 2.
