So, I was able to make a graph, but I need to graph the constants a and b as they change to determine the minimum value of a and b of the function (energy). Unfortunately, I am receiving the error:

"Warning, unable to evaluate the function to numeric values in the region; see the plotting command's help page to ensure the calling sequence is correct"

which is confusing me as I do not know how to correct this. I need the function to be fixed for some specific x and y (I chose x=2 and y=0 as some dummy values) which I am probably doing incorrectly. Thank you. I'm new to Maple so this is a learning experience all by itself.

restart;

psi := proc (a, b) options operator, arrow; exp((-1)*.5*((a+b)*x+(a-b)*y))/((a*b)^1.5*((1/(a+b)^2+1/(a+b)^3)/(a-b)-(1/(a-b)^3-1/(a-b)^2)/(a+b))*exp(-2*b)+((1/(a-b)^2+1/(a-b)^3)/(a+b)-(1/(a+b)^2+1/(a+b)^3)/(a-b))*exp(-2*a)+1/(2/(3*a+3*b)+2/(a+b)^2+2/(a+b)^3))+exp((-1)*.5*((a+b)*x-(a-b)*y)) end proc;

schro := 4*(x^2-1)*(diff(psi(x, y), x, x))/(x^2-y^2)+2*x*(diff(psi(x, y), x))-(y^2-1)*(diff(psi(x, y), y, y))-2*y*(diff(psi(x, y), y))+(-2/(x+y)-2/(x-y)+1)*psi(x, y);

x := 1; y := 0;

plot3d(schro, a = 0 .. 100, b = 0 .. 100)