Nonvariational Orbital Optimization Techniques for the AP1roG Wave Function Academic Article uri icon

  • Overview
  • Research
  • Identity
  • Additional Document Info
  • View All


  • We introduce new nonvariational orbital optimization schemes for the antisymmetric product of one-reference orbital geminal (AP1roG) wave function (also known as pair-coupled cluster doubles) that are extensions to our recently proposed projected seniority-two (PS2-AP1roG) orbital optimization method [ J. Chem. Phys. 2014 , 140 , 214114 )]. These approaches represent less stringent approximations to the PS2-AP1roG ansatz and prove to be more robust approximations to the variational orbital optimization scheme than PS2-AP1roG. The performance of the proposed orbital optimization techniques is illustrated for a number of well-known multireference problems: the insertion of Be into H2, the automerization process of cyclobutadiene, the stability of the monocyclic form of pyridyne, and the aromatic stability of benzene.


  • Boguslawski, Katharina
  • Tecmer, Paweł
  • Bultinck, Patrick
  • De Baerdemacker, Stijn
  • Van Neck, Dimitri
  • Ayers, Paul

publication date

  • November 11, 2014