This is the code I have in my mathematica notebook. I want to find the eigenvalues of the matrix I created called Hmatrix as defined below. However when I type Eigenvalues[Hmatrix] I get the Hmatrix back with an extra set of brackets preceded by "Eigenvalues" again. Essentially, I am not getting the eigenvalues of this matrix and I wish to know what sort of syntax I have to use to find the eigenvalues of my Hmatrix.
ϵs = -13.6;
ϵso = -29.1;
ϵp = -14.1;
ssσ = -7.20;
spσ = 9.46;
θ = (π - β/2);
Hmatrix :=
MatrixForm[{{ϵs, 0, ssσ,
Cos[θ]*spσ, -Sin[θ]*spσ,
0}, {0, ϵs,
ssσ, -Cos[θ]*spσ, -Sin[θ]*spσ,
0}, {ssσ, ssσ, ϵso, 0, 0,
0}, {Cos[θ]*spσ, Cos[θ]*spσ,
0, ϵp, 0,
0}, {-Sin[θ]*spσ, -Sin[θ]*spσ, 0,
0, ϵp, 0}, {0, 0, 0, 0, 0, ϵp}}]
Hmatrixis not an array of numbers: it is aMatrixFormobject. Get rid ofMatrixFormand try it. – whuber Mar 13 '13 at 21:09