05138nam 2200577 450 991020884510332120170821200810.01-119-01957-51-119-01955-91-119-01956-7(CKB)3710000000222714(EBL)1767029(MiAaPQ)EBC1767029(EXLCZ)99371000000022271420140831e20122000 uy 0engur|n|---|||||rdacontentrdamediardacarrierMolecular electronic-structure theory /Trygve Helgaker, Poul Jorgensen, Jeppe OlsenChichester, England :John Wiley & Sons Ltd.,2012.©20001 online resource (940 p.)Description based upon print version of record.0-471-96755-6 1-118-53147-7 Includes bibliographical references and index.Cover; Title Page; Copyright; Contents; Preface; Overview; Programs used in the preparation of this book; 1 Second Quantization; 1.1 The Fock space; 1.2 Creation and annihilation operators; 1.2.1 Creation operators; 1.2.2 Annihilation operators; 1.2.3 Anticommutation relations; 1.3 Number-conserving operators; 1.3.1 Occupation-number operators; 1.3.2 The number operator; 1.3.3 Excitation operators; 1.4 The representation of one- and two-electron operators; 1.4.1 One-electron operators; 1.4.2 Two-electron operators; 1.4.3 The molecular electronic Hamiltonian1.5 Products of operators in second quantization1.5.1 Operator products; 1.5.2 The canonical commutators; 1.6 First- and second-quantization operators compared; 1.7 Density matrices; 1.7.1 The one-electron density matrix; 1.7.2 The two-electron density matrix; 1.7.3 Density matrices in spin-orbital and coordinate representations; 1.8 Commutators and anti commutators; 1.9 Nonorthogonal spin orbitals; 1.9.1 Creation and annihilation operators; 1.9.2 One- and two-electron operators; 1.9.3 Biorthogonal operators; References; Further reading; Exercises; Solutions; 2 Spin in Second Quantization2.1 Spin functions2.2 Operators in the orbital basis; 2.2.1 Spin-free operators; 2.2.2 Spin operators; 2.2.3 Mixed operators; 2.3 Spin tensor operators; 2.3.1 Spin tensor operators; 2.3.2 Creation and annihilation operators; 2.3.3 Two-body creation operators; 2.3.4 Excitation operators; 2.3.5 Singlet excitation operators; 2.4 Spin properties of determinants; 2.4.1 General considerations; 2.4.2 Spin projection of determinants; 2.4.3 Total spin of determinants; 2.5 Configuration state functions; 2.6 The genealogical coupling scheme; 2.6.1 Representations of determinants and CSFs2.6.2 Genealogical coupling2.6.3 Coupling coefficients; 2.6.4 An example: three electrons in three orbitals; 2.6.5 Completeness and orthonormality; 2.6.6 Transformations between determinant and CSF bases; 2.6.7 Genealogical coupling of operators; 2.7 Density matrices; 2.7.1 Orbital-density matrices; 2.7.2 Spin-density matrices; 2.7.3 Density functions; References; Further reading; Exercises; Solutions; 3 Orbital Rotations; 3.1 Unitary transformations and matrix exponentials; 3.1.1 Matrix exponentials; 3.1.2 Exponential representations of unitary matrices; 3.1.3 Special unitary matrices3.1.4 Orthogonal matrices3.1.5 Evaluation of matrix exponentials; 3.1.6 Nonunitary transformations; 3.2 Unitary spin-orbital transfonnations; 3.2.1 Unitary matrix expansions of creation and annihilation operators; 3.2.2 Exponential unitary transfonnations of the elementary operators; 3.2.3 Exponential unitary transfonnations of states in Fock space; 3.3 Symmetry-restricted unitary transfonnations; 3.3.1 The need for symmetry restrictions; 3.3.2 Symmetry restrictions in the spin-orbital basis; 3.3.3 Symmetry restrictions in the orbital basis; 3.4 The logarithmic matrix function3.4.1 Definition of the logarithmic matrix functionAb initio quantum chemistry has emerged as an important tool in chemical research and is appliced to a wide variety of problems in chemistry and molecular physics. Recent developments of computational methods have enabled previously intractable chemical problems to be solved using rigorous quantum-mechanical methods.This is the first comprehensive, up-to-date and technical work to cover all the important aspects of modern molecular electronic-structure theory. Topics covered in the book include:* Second quantization with spin adaptation* Gaussian basis sets and molecular-integral evaluation* HMolecular structureElectronic structureElectronic books.Molecular structure.Electronic structure.541.28Helgaker Trygve597004Jørgensen Poul1944-Olsen JeppeMiAaPQMiAaPQMiAaPQBOOK9910208845103321Molecular electronic-structure theory2258747UNINA00867nam a22002291i 450099100409404970753620020617150110.0020617s1983 it |||||||||||||||||ita b11911153-39ule_instARCHE-000098ExLDip.to Filologia Ling. e Lett.itaA.t.i. Arché s.c.r.l. Pandora Sicilia s.r.l.Alberti, Barbara532903Il signore e servito :romanzo /Barbara AlbertiMilano :A. Mondadori,1983170 p. ;22 cmScrittori italiani e stranieri.b1191115328-04-1701-04-03991004094049707536LE008 TS L I 4012008000397555le008-E0.00-l- 00000.i1217919x01-04-03Signore e servito914310UNISALENTOle00801-04-03ma -itait 31