next up previous contents index
Next: Optimization of General Coordinates Up: Program Relax Previous: Program Relax   Contents   Index


relax drives and controls a non-linear optimization procedure to locate the minimum (or a stationary point) of a function $ f(x)$. In TURBOMOLE $ f$ is always the electronic energy, and the coordinates $ x$ will be referred to as general coordinates. They include The optimization employs an iterative procedure based on gradients $ \nabla f$ of the current and, if available, previous iterations. Various procedures can be applied: steepest descent, Pulay's DIIS, quasi-Newton, conjugate gradients, as well as combinations of them. relax carries out: The mode of operation is chosen by the keywords $optimize and $interconversion and the corresponding options, which will be described in the following sections.