Namaste
To my limited knowledge there are three more beejas to be added to the Mahamantra.
Aum Haum Aum Joom Sah Aum Bhoorbhoovahsvarom Aum Trayambakam Yajamahe Sugandhim Pushti Vardhanam Urvaarukamiva Bandhanaam Mrityor Mooksheeya mamritaat Bhoorbhuvahsvarom Sah Joom Haum Aum

Trayambakam means the three eyed one who has Sun Moon and Agni as His eyes. Also the lord of the three vedas, the three gunas rajas tamas and sattva, the three worlds Bhuloka bhuvarloka suvarloka, the three kinds of dangers, the three shaktis iccha kriya and jnana, the three phases of creation with A kara, sustenance with U kara and transformation with M akara that is AUM, the three phases of time past present and future and also three types of dehas or bodies which contain the five koshas that is stoola sharira gross body,linga sharira or subtle body and karana sharira or causal body and three types of karma sanchita,agama and prarabdha karmas. The lord of all these threes ofcourse liberates us from the fear of death and elevate our prana to the highest level of consiousness free from bondage of cultural and human standards of perceived morality and evil. This mantra gives us the real nature of the creation. However this mantra speeds up the negative karma burning and can cause unpleasant side effects in the beginning. Once we endure all of that there is only bliss truth and consciousness.