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
    Analytical first derivatives of the energy in the MNDO half-electron open-shell treatment (1996)
    Springer
    Theoretical chemistry accounts 93 (1996), S. 87-99 
    Details
    ISSN: 1432-2234
    Keywords: MNDO ; Half-electron method ; Analytical derivatives ; Z-vector
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Using the Z-vector formalism the analytical gradient of the energy in the half-electron open-shell treatment is derived and implemented for semiempirical MNDO-type methods. The computation time is shown to scale asO(N 3) with the size of the system, with the memory requirements growing asO(N 2). The evaluation of the analytical gradient is significantly faster than the half-electron SCF calculation, so that routine full geometry optimizations become possible for large open-shell systems. The approach can easily be extended to the treatment of the small CI expansions typically encountered in semiempirical computations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01113550
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Analytical first derivatives of the energy for small CI expansions (1997)
    Springer
    Theoretical chemistry accounts 98 (1997), S. 1-4 
    Details
    ISSN: 1432-2234
    Keywords: Key words: MNDO ; Configuration interaction ; Analytical derivatives ; Z-vector
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract. Using the Z-vector formalism the analytical gradient of the energy in small CI expansions is derived and implemented for semiempirical MNDO-type methods. The computation time is shown to scale as O(N 3) with the size of the system, with the memory requirements growing as O(N 2). The evaluation of the analytical gradient is significantly faster than the underlying SCF and CI calculations, so that routine full geometry optimizations at the semiempirical CI level become possible for large systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002140050271
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The Equilibrium Structure of Methyl Fluoride (1999)
    Springer
    Structural chemistry 10 (1999), S. 129-133 
    Details
    ISSN: 1572-9001
    Keywords: Methyl fluoride ; rotational constants ; equilibrium structure ; ab initio
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The equilibrium structure of CH3F has been determined using new sets of accurate rotational constants that have been determined by taking into account all the interactions between the excited vibrational states. This experimental structure is in excellent agreement with the equilibrium geometry calculated at the CCSD(T) level of theory with the cc-pV(5, Q)Z basis set (including corrections for the core correlation and for the effect of diffuse functions on fluorine). Finally, the experimental and ab initio structures have been combined by a least-squares analysis. The results are $$r_e \left( {C - C} \right) = 1.087\left( 1 \right){\AA},r_e \left( {C - F} \right) = 1.383\left( 1 \right){\AA},and\angle _e \left( {HCH} \right) = 110.2\left( 1 \right)^ \circ $$ , and L e(HCH) = 110.2 (1)°, where the uncertainties shown in parentheses correspond to three standard deviations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022085314343
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Analytical first derivatives of the energy in the MNDO half-electron open-shell treatment (1996)
    Springer
    Theoretica chimica acta 93 (1996), S. 87-99 
    Details
    ISSN: 0040-5744
    Keywords: Key words:MNDO - Half-electron method - Analytical derivatives - Z-vector
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary. Using the Z-vector formalism the analytical gradient of the energy in the half-electron open-shell treatment is derived and implemented for semiempirical MNDO-type methods. The computation time is shown to scale as $O(N^3)$ with the size of the system, with the memory requirements growing as $O(N^2)$ . The evaluation of the analytical gradient is significantly faster than the half-electron SCF calculation, so that routine full geometry optimizations become possible for large open-shell systems. The approach can easily be extended to the treatment of the small CI expansions typically encountered in semiempirical computations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01113550
    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...