N

unsigned integer, read only

returns the number of determinants saved within the wavefunction.

We can define the function: $$|\psi\rangle = \left(\frac{1}{\sqrt{4}} a^{\dagger}_0 a^{\dagger}_1 + \frac{1}{\sqrt{4}} a^{\dagger}_0 a^{\dagger}_2 + (1+I)\frac{1}{\sqrt{4}} a^{\dagger}_1 a^{\dagger}_2 \right)|0\rangle,$$ which has three determinants and psi.N thus is equal to three.

Example.Quanty

NF=3
NB=0
psi = NewWavefunction(NF, NB, {{"110",sqrt(1/4)},{"101",sqrt(1/4)},{"011",(1+I)*sqrt(1/4)}})
print(psi.N)

3