Phase of Orbital/Wavefunctions in Hydrogen 2px

[Mark S 2014]

What exactly are the phases of orbitals/wavefunctions, for example the 2px orbital in hydrogen, what does it mean for the two lobes to be in different phases ?

 

[Greg Bernhardt]

Thanks for the post! Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?

 

[Mark S 2014]

Yes I get that it's a poorly worded question. I'm in my first year of a chemistry degree and we are just going through atomic orbitals. I just don't really get the significance of the different phases in each lobe, I get that the wavefunction is like a wave and has positive and negative values at certain points. I just don't get what this means really. How does a positive phase differ from a negative phase ?

 

[moriheru]

In QM there are several ways of writing things a)Dirac notation b) Hilberts matrix formulation c)Schrodingers wavefunction and so on
The wavefunction can be described using ket and bra notation, but in general you use the wavefunction when you are talking about probability amplitudes, for exapmle the Schrodinger equation for hydrogen atoms which consits of a radial part and angluar part...

 

[DrClaude]

I just don't really get the significance of the different phases in each lobe, I get that the wavefunction is like a wave and has positive and negative values at certain points. I just don't get what this means really. How does a positive phase differ from a negative phase ?

To say that "the wavefunction is like a wave" is not completely correct. What is important here is that the wavefunction is like a function, since it is a function, with complex values. In the case of a p orbital, that function is real, and can have a positive or a negative value, depending on the position. If you consider the probability of finding the electron in some volume in space, the sign of the wavefunction is not important since the probability is proportional to $| \psi(\mathbf{r})|^2$. However, the sign can be important when considering overlaping orbitals, as the sign can lead to constructive or destructive interference: in some places, the orbitals will add to each other, elsewhere they will cancel each other out.

 

[Mark S 2014]

Thanks, much appreciated.