Goddess Raja shymala or Raja Matangi mantra takes the following form,

The second divinity is Mantrini (conseller to the mother-goddess). She is also called Shyamala (dark in complexion), and Mathangi(or RajaMathangi, in her capacity to function like the gateway to Srividya).

Goddess Raja shymala or Raja Matangi mantra takes the following form,

AIM  KLIM  SAU  AIM  HRIM  SHRIM  OM

OR alternatively,

HRIM  SHRIM  KLIM  AIM

OR again

AIM  HRIM  SHRIM  AIM  KLIM  SAU   OM  NAMO  BHAGAVATI  RAJAMATANGESWARI  AIM

She symbolizes the second unit of panchadasi mantra and therefore she hasthis formula form,

HESTRAIM  HA  SA  KA  HA  LA  HRIM  HESTRAUH