Differences
This shows you the differences between two versions of the page.
Both sides previous revision Previous revision | |||
relativistic_corrections [2020/06/16 14:42] – link to duplicate example may | relativistic_corrections [2024/01/08 13:24] (current) – external edit 127.0.0.1 | ||
---|---|---|---|
Line 1: | Line 1: | ||
+ | ====== Relativistic corrections ====== | ||
+ | There are three ways in Molpro | ||
+ | |||
+ | - Use the Douglas-Kroll-Hess or eXact-2-Component (X2C) relativistic one-electron integrals. | ||
+ | - Compute a perturbational correction using the Cowan-Griffin operator (see section [[program control# | ||
+ | - Use relativistic effective core potentials (see section [[effective core potentials]]). | ||
+ | |||
+ | ===== Using the Douglas–Kroll–Hess or eXact-2-Component Hamiltonians ===== | ||
+ | |||
+ | For all-electron calculations, | ||
+ | |||
+ | '' | ||
+ | '' | ||
+ | '' | ||
+ | |||
+ | or for X2C by setting | ||
+ | |||
+ | '' | ||
+ | somewhere in the input before the first energy calculation. | ||
+ | |||
+ | Alternatively, | ||
+ | |||
+ | '' | ||
+ | |||
+ | or | ||
+ | |||
+ | '' | ||
+ | |||
+ | The DKH option '' | ||
+ | |||
+ | The value of '' | ||
+ | |||
+ | * **'' | ||
+ | * **'' | ||
+ | * **'' | ||
+ | * **'' | ||
+ | * **'' | ||
+ | |||
+ | **Example: | ||
+ | |||
+ | |'' | ||
+ | |'' | ||
+ | |||
+ | Up to fourth order ('' | ||
+ | |||
+ | For details on the infinite-order DKH Hamiltonians see\\ | ||
+ | M. Reiher, A. Wolf, JCP **121**, 2037–2047 (2004),\\ | ||
+ | M. Reiher, A. Wolf, JCP **121**, 10945–10956 (2004). | ||
+ | |||
+ | For details on the different parametrizations of the unitary transformations see\\ | ||
+ | A. Wolf, M. Reiher, B. A. Hess, JCP **117**, 9215–9226 (2002). | ||
+ | |||
+ | The current implementation is the polynomial-cost algorithm by Peng and Hirao: D. Peng, K. Hirao, JCP 130, 044102 (2009).\\ | ||
+ | A detailed comparison of the capabilities of this implementation as well as the current implementation of the X2C approach is provided in:\\ | ||
+ | D. Peng, M. Reiher, TCA 131, 1081 (2012). | ||
+ | |||
+ | See [[program_control# |