ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Internally contracted multiconfiguration-reference configuration interaction calculations for excited states (1992)
    Springer
    Theoretical chemistry accounts 84 (1992), S. 95-103 
    Details
    ISSN: 1432-2234
    Keywords: Quantum chemistry ; Configuration interaction ; Excited states
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The calculation of electronically excited states with the internally contracted multiconfiguration-reference configuration interaction (CMRCI) method is discussed. A straightforward method, in which contracted functions for all states are included in the basis, is shown to be very accurate and stable even in cases of narrow avoided crossings. However, the expense strongly increases with the number of states. A new method is proposed, which employs different contracted basis sets for each state, and in which eigensolutions of the Hamiltonian are found using an approximate projection operator technique. The computational effort for this method scales only linearly with the number of states. The two methods are compared for various applications.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01117405
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    A comparison of variational and non-variational internally contracted multiconfiguration-reference configuration interaction calculations (1990)
    Springer
    Theoretical chemistry accounts 78 (1990), S. 175-187 
    Details
    ISSN: 1432-2234
    Keywords: Variational ; Non-variational ; Configuration interaction ; Diatomic molecules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The internally contracted multiconfiguration-reference configuration interaction (CMRCI) method and several non-variational variants of this method (averaged coupled pair approximation (ACPF), quasidegenerate variational perturbation theory (QD-VPT), linearized coupled pair many electron theory (LCPMET)) have been employed to compute potential energy functions and other properties for a number of diatomic molecules (F2, O2, N2, CN, CO) using large basis sets and full valence CASSCF reference wavefunctions. In most cases the variational CMRCI wavefunctions yield more accurate spectroscopic constants than any of the employed non-variational methods. Several basis sets are compared for the N2 molecule. It is found that atomic natural orbital (ANO) contractions led to significant errors in the computedr e , ω e , andD e values.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01112867
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...