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化學數學(一). The Mathematics for Chemists (I) (Fall Term, 2004) (Fall Term, 2005) (Fall Term, 2006) Department of Chemistry National Sun Yat-sen University. Review: General. Dot, cross, orthonormal basis, gradient, convergence, curl (rot). Order-lowering, row and column operations,
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化學數學(一) The Mathematics for Chemists (I) (Fall Term, 2004)(Fall Term, 2005)(Fall Term, 2006)Department of ChemistryNational Sun Yat-sen University
Review: General Dot, cross, orthonormal basis, gradient, convergence, curl (rot) Order-lowering, row and column operations, Triangular form, linear inhomogeneous equations • Vector • Determinant • Matrix • 1st Order LODE • 2nd Order LODE • PDE • Orthogonal Expansion Linear homogeneous equations Transpose, cofactor, adjoint, inverse Symmetric,orthogonal,Hermitian,unitary Trace, eigenvalue, eigenvector, diagonalization, Canonical form of quadratic forms Constant coefficient inhomogeneous Variable coefficient inhomogeneous Constant coefficient + special inhomogeneous Variable coefficient + homogeneous: (Associated) Legendre, Hermite,(Associated) Laguerr Separation of variables: PDE ODE General expansion, Fourier series, FT
azk ayj axi c x3 b x2 a x1 Base Vectors Orthogonal basis: Nonorthogonal basis:
Vector Spaces … Orthonormal basis General orthogonal basis:
S b a L S V Major Theorems in Integration
… The Solutions of Linear Equations Cramer’s Rule:
Properties of Determinants 2. Multiplication by a scalar: 1. Transpose: 3. Zero row or column: 4. Addition rule: 5. Interchange of rows/columns: antisymmetry: 6. Two equal rows/columns: 8. Additions of rows/columns: 7. Proportional rows/columns: 9. Differentiation:
Square Matrix: Transpose and Inverse symmetric matrix If
Orthogonal Matrices: General Cases Again, Kronecker symbol.
Other Useful Matrices in Chemistry 1. Hermitian matrices: (Hermitian matrix is the complex extension of symmetric matrix) • For real matrices, Hermitian means symmetric. • All physical observables are Hermitian matrices. 2. Unitary matrices: (Unitary matrix is the complex extension of orthogonal matrix) For real matrices, unitary means orthogonal.
Matrix Algebra The associative law: The distributive law: The (non-)commutative law: Commutator:
The Matrix Eigenvalue Problem and Secular Equations The condition for the existence of nontrivial solution: (secular determinant)
Matrix Diagonalization Diagonalization of a square matrix is essentially the same as finding the eigenvalues and their respective eigenvectors.
Solving First Order ODE Separable Equations: + initial conditions First-order linear equations:
Reduction to Separable Form: Homogeneous Equations For n=0: Example:
The determination of the coefficient(s) in yp is obtained by substituting it back to the inhomogeneous equation. However, if yp is already in yhthen the general solution should be: where the choice of c(x): If the characteristic equation of the corresponding homogeneous equation has two (real or complex) roots, then c(x) =x, or else, c(x)=x2 . If r(x) is the sum of terms given in above table, the total yp(x) is the sum of respectiveypof all terms. [This leads to a method of series expansion for general r(x) ]
Inhomogeneous, linear, variable coefficients: Second-Order ODE: Special Cases of Variable Coefficients It’s hard or impossible to obtain the solution of a general second-order ODE
The Associated Legendre Functions Under conditions: The particular solutions are associated Legendre functions:
The Laguerre Equation n: real number Laguerre polynomials: Recurrence relation:
Associated Laguerre Functions The associated Laguerre equation It’s solution is associated Laguerre polynomials: they arise in the radial part of the wavefunctions of hydrogen atom in the form of associated Laguerre functions: which satisfy: and are orthogonal with respect to the weight functionx2 in the interval [0,∞]:
Hydrogen-Like Atoms Laguerre polynomails Normalization factor
Separation of Variables: Turn PDE into ODE A 2D problem reduced to two 1D problems!
f(x) +A x 0 -l l -A Fourier Series
f(x) +A x 0 -l l -A Example: Fourier Series
Fourier Transform Pairs if exists.
a/π y 0 Example FT