Defects in Silicon with the CRYSTAL Code

A silicon atom is substituted by a nitrogen atom. The unpaired electron leads to only one possible spin state: the doublet (S_z=1/2). Click for the vibrational normal modes.

Two nitrogen atoms substitute two nearby silicon atoms. Each nitrogen is three-fold coordinated and thus the defect can be present in a singlet spin state. Click for the vibrational normal modes.

A silicon atom is removed and a nearby silicon atom is substituted by a nitrogen atom. The three unpaired electrons lead to two possible spin states: the doublet (S_z=1/2) and the quadruplet (S_z=3/2). Click for the vibrational normal modes of the doublet spin state.

A silicon atom is removed and two nearby silicon atoms are substituted by the same number of nitrogen atoms. The two unpaired electrons lead to two possible spin states: the singlet (S_z=0) and the triplet (S_z=1). Click for the vibrational normal modes of the singlet spin state.

A silicon atom is removed and three nearby silicon atoms are substituted by the same number of nitrogen atoms. The unpaired electron leads to one possible spin states: the doublet (S_z=1/2). Click for the vibrational normal modes.

A silicon atom is removed and the four nearby silicon atoms are substituted by the same number of nitrogen atoms. The defect is in a singlet (S_z=0) spin state. Click for the vibrational normal modes.

Two nearby silicon atom are removed and two nearby silicon atoms are substituted by the same number of nitrogen atoms. The four unpaired electrons lead to three possible spin states: the singlet (S_z=0), the triplet (S_z=1) and the quintuplet (S_z=2). Click for the vibrational normal modes of the singlet spin state.

A nitrogen atom is added to a bond-centered position. The unpaired electron leads to only one possible spin state: the doublet (S_z=1/2). Click for the vibrational normal modes.

Two nitrogen atoms are added. Each nitrogen is three fold-coordinated and thus the defect can be present in a singlet spin state. Click for the vibrational normal modes.

One silicon atoms is substituted by nitrogen atom and one nitrogen atom is added to a bond-centered position. The defect is in a singlet (S_z=0) spin state. Click for the vibrational normal modes of the doublet spin state.

Two nitrogen atoms and one silicon atom are added. The defect is in a singlet (S_z=0) spin state. Click for the vibrational normal modes of the singlet spin state.

One silicon atom is substituted by nitrogen atom and one nitrogen atom is added so they occupy the same tetrahedral position alond <100> direction. The defect is in a singlet (S_z=0) spin state. Click for the vibrational normal modes.

One silicon atom is substituted by nitrogen atom and one carbon atom is added so they occupy the same tetrahedral position alond <100> direction. The defect is in a doublet (S_z=1/2) spin state. Click for the vibrational normal modes.

One nitrogen atom is added so silicon and nitrogen occupy the same tetrahedral position alond <100> direction. The defect is in a doublet (S_z=1/2) spin state. Click for the vibrational normal modes.

A silicon atom is substituted by a nitrogen atom. The unpaired electron leads to only one possible spin state: the doublet (S_z=1/2). Click for the vibrational normal modes.

The oxygen atom occupies a bond centered, {111} oriented interstitial position between two silicon atoms with a Si-O-Si angle of about 165°. Click for the vibrational normal modes.

Two interstitial oxygen atoms are vicinal to the same silicon atom. Click for the vibrational normal modes.

Two interstitial oxygen atoms are separated by one Si-Si bond. Click for the vibrational normal modes.

Two interstitial oxygen atom are separated by two Si-Si bonds. Click for the vibrational normal modes.

Four interstitial oxygen atom are inserted between the bonds connecting one silicon atom with its four first neighbours. Click for the vibrational normal modes.