I. First Principles Cluster Calculations for the Electronic Structures of CuO7 Octahedron and CuO5 Pyramid

1997 ◽  
Vol 11 (32) ◽  
pp. 3733-3750 ◽  
Author(s):  
Akihiro Sano ◽  
Mikio Eto ◽  
Hiroshi Kamimura
Keyword(s):  
First Principles ◽  
Electronic Structures ◽  
Field Method ◽  
Strongly Correlated ◽  
Cluster Systems ◽  
Consistent Field ◽  
Cluster Calculations ◽  
Self Consistent ◽  
Self Consistent Field

In this paper we first describe the multi-configuration self-consistent field method with configuration interaction (MCSCF-CI) which is a variational method most suitable for strongly-correlated cluster systems. Then the calculated results of CuO 6 cluster embedded in hole-doped La 2-x Sr x CuO 4 and of CuO 4 cluster in the electron-doped Nd 2-x Ce x CuO 4 are reviewed. Finally the calculated results on the electronic structure of CuO 5 pyramid embedded in the insulating YBa 2 Cu 3 O 6 and superconducting YBa2Cu3O7 are newly presented. In the latter case we will clarify an important role of the Cu-O chain in the electronic and superconducting state of YBa2Cu3O7 .

A First Principles Approach for Partitioning Linear Response Properties into Additive and Cooperative Contributions

2018 ◽  
Author(s):  
Daniel Lambrecht ◽  
Eric Berquist
Keyword(s):  
First Principles ◽  
Linear Response ◽  
Building Blocks ◽  
Field Method ◽  
Response Property ◽  
Response Properties ◽  
Consistent Field ◽  
Molecular Building Blocks ◽  
Self Consistent ◽  
Self Consistent Field

We present a first principles approach for decomposing molecular linear response properties into orthogonal (additive) plus non-orthogonal/cooperative contributions. This approach enables one to 1) identify the contributions of molecular building blocks like functional groups or monomer units to a given response property and 2) quantify cooperativity between these contributions. In analogy to the self consistent field method for molecular interactions, SCF(MI), we term our approach LR(MI). The theory, implementation and pilot data are described in detail in the manuscript and supporting information.

scholarly journals Spin State Ordering in Metal-Based Compounds Using the Localized Active Space Self-Consistent Field Method

2019 ◽  
Author(s):  
Riddhish Pandharkar ◽  
Matthew R. Hermes ◽  
Christopher J. Cramer ◽  
Laura Gagliardi
Keyword(s):  
Spin State ◽  
Computational Cost ◽  
Field Method ◽  
Basis Set ◽  
Strongly Correlated ◽  
Active Space ◽  
Embedding Theory ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field

<p>Quantitatively accurate calculations for spin state ordering in transition-metal complexes typically demand a robust multiconfigurational treatment. The poor scaling of such methods with increasing size makes them impractical for large, strongly correlated systems. Density matrix embedding theory (DMET) is a fragmentation approach that can be used to specifically address this challenge. The single-determinantal bath framework of DMET is applicable in many situations, but it has been shown to perform poorly for molecules characterized by strong correlation when a multiconfigurational self-consistent field solver is used. To ameliorate this problem, the localized active space self-consistent field (LASSCF) method was recently described. In this work, LASSCF is applied to predict spin state energetics in mono- and di-iron systems and we show that the model offers an accuracy equivalent to CASSCF but at a substantially lower computational cost. Performance as a function of basis set and active space is also examined.<br></p>

A First Principles Approach for Partitioning Linear Response Properties into Additive and Cooperative Contributions

2018 ◽  
Author(s):  
Daniel Lambrecht ◽  
Eric Berquist
Keyword(s):  
First Principles ◽  
Linear Response ◽  
Building Blocks ◽  
Field Method ◽  
Response Property ◽  
Response Properties ◽  
Consistent Field ◽  
Molecular Building Blocks ◽  
Self Consistent ◽  
Self Consistent Field

We present a first principles approach for decomposing molecular linear response properties into orthogonal (additive) plus non-orthogonal/cooperative contributions. This approach enables one to 1) identify the contributions of molecular building blocks like functional groups or monomer units to a given response property and 2) quantify cooperativity between these contributions. In analogy to the self consistent field method for molecular interactions, SCF(MI), we term our approach LR(MI). The theory, implementation and pilot data are described in detail in the manuscript and supporting information.

scholarly journals Spin State Ordering in Metal-Based Compounds Using the Localized Active Space Self-Consistent Field Method

2019 ◽  
Author(s):  
Riddhish Pandharkar ◽  
Matthew R. Hermes ◽  
Christopher J. Cramer ◽  
Laura Gagliardi
Keyword(s):  
Spin State ◽  
Computational Cost ◽  
Field Method ◽  
Basis Set ◽  
Strongly Correlated ◽  
Active Space ◽  
Embedding Theory ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field

<p>Quantitatively accurate calculations for spin state ordering in transition-metal complexes typically demand a robust multiconfigurational treatment. The poor scaling of such methods with increasing size makes them impractical for large, strongly correlated systems. Density matrix embedding theory (DMET) is a fragmentation approach that can be used to specifically address this challenge. The single-determinantal bath framework of DMET is applicable in many situations, but it has been shown to perform poorly for molecules characterized by strong correlation when a multiconfigurational self-consistent field solver is used. To ameliorate this problem, the localized active space self-consistent field (LASSCF) method was recently described. In this work, LASSCF is applied to predict spin state energetics in mono- and di-iron systems and we show that the model offers an accuracy equivalent to CASSCF but at a substantially lower computational cost. Performance as a function of basis set and active space is also examined.<br></p>

Quantum mechanical computations on very large molecular systems: The local self-consistent field method

1994 ◽  
Vol 15 (3) ◽  
pp. 269-282 ◽  
Author(s):  
Vincent Théry ◽  
Daniel Rinaldi ◽  
Jean-Louis Rivail ◽  
Bernard Maigret ◽  
György G. Ferenczy
Keyword(s):  
Field Method ◽  
Quantum Mechanical ◽  
Molecular Systems ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Quantum Mechanical Computations
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