Quantum Monte Carlo: hydrogen atom

Inserting this wave function into the expression for the local energy \( E_L \) gives $$ E_L(\rho)=-\frac{1}{\rho}- \frac{\alpha}{2}\left(\alpha-\frac{2}{\rho}\right). $$ A simple variational Monte Carlo calculation results in

\( \alpha \) \( \langle H \rangle \) \( \sigma^2 \) \( \sigma/\sqrt{N} \)
7.00000E-01 -4.57759E-01 4.51201E-02 6.71715E-04
8.00000E-01 -4.81461E-01 3.05736E-02 5.52934E-04
9.00000E-01 -4.95899E-01 8.20497E-03 2.86443E-04
1.00000E-00 -5.00000E-01 0.00000E+00 0.00000E+00
1.10000E+00 -4.93738E-01 1.16989E-02 3.42036E-04
1.20000E+00 -4.75563E-01 8.85899E-02 9.41222E-04
1.30000E+00 -4.54341E-01 1.45171E-01 1.20487E-03