Hybrid sp3Orbitals

r2s[ theta_ , phi_ ] := 1.
 

r2px[ theta_ , phi_ ] := Sin[ theta ] Cos[ phi ] 
 

r2py[ theta_ , phi_ ] :=  Sin[ theta ] Sin[ phi ] 
 

r2pz[ theta_ , phi_ ] :=  Cos[ theta ] 

Linear combination of the 2s and 2p orbitals

Four sp3 Hybrid orbitals

Superposition of four s orbitals

figure1 =
ParametricPlot3D[ {
{(rsp3a[ theta, phi ]) Sin[ theta ] Cos[ phi ],
 (rsp3a[ theta, phi ]) Sin[ theta ] Sin[ phi ], 
 (rsp3a[ theta, phi ]) Cos[ theta ]
},
{(rsp3b[ theta, phi ]) Sin[ theta ] Cos[ phi ],
 (rsp3b[ theta, phi ]) Sin[ theta ] Sin[ phi ], 
 (rsp3b[ theta, phi ]) Cos[ theta ]
},
{(rsp3c[ theta, phi ]) Sin[ theta ] Cos[ phi ],
 (rsp3c[ theta, phi ]) Sin[ theta ] Sin[ phi ], 
 (rsp3c[ theta, phi ]) Cos[ theta ]
},
{(rsp3d[ theta, phi ]) Sin[ theta ] Cos[ phi ],
 (rsp3d[ theta, phi ]) Sin[ theta ] Sin[ phi ], 
 (rsp3d[ theta, phi ]) Cos[ theta ]}
}, 
{ theta, 0, Pi  }, { phi, 0, 2 Pi }, 
ViewPoint->{2.0, 4.0, 3.250}, Boxed -> False, AspectRatio -> Automatic, PlotPoints->50,PlotRange->{{-1.5,1.5},{-1.5,1.5},{-1.5,1.5}} ];

Side view

Show[ figure1, ViewPoint->{1.620, -1.600, 2.070},PlotRange->{{-1.5,1.5},{-1.5,1.5},{-1.5,1.5}}]

Top view

Show[ figure1,ViewPoint->{1.620, -1.600, 15.000},PlotRange->{{-1.5,1.5},{-1.5,1.5},{-1.5,1.5}} ]

Single sp3 Orbital

figure2 =
ParametricPlot3D[ {(rsp3a[ theta, phi ]) Sin[ theta ] Cos[ phi ],
                   (rsp3a[ theta, phi ]) Sin[ theta ] Sin[ phi ], 
                   (rsp3a[ theta, phi ]) Cos[ theta]}, 
{theta, 0, Pi  }, { phi, 0, 2 Pi },ViewPoint->{-2.549, 2.218, 0.177},PlotRange->{{-.5,1.5},{-.5,1.5},{-.5,1.5}},
Boxed -> False,PlotPoints->50 ]

figure4 =
ParametricPlot3D[ {(nrsp3a[ theta, phi ]) Sin[ theta ] Cos[ phi ],
                   (nrsp3a[ theta, phi ]) Sin[ theta ] Sin[ phi ], 
                   (nrsp3a[ theta, phi ]) Cos[ theta]}, 
{theta, 0, Pi  }, { phi, 0, 2 Pi },ViewPoint->{-2.549, 2.218, 0.177},PlotRange->{{-.25,.5},{-.25,.5},{-.25,.5}},
Boxed -> False,PlotPoints->50 ]