ॐ ह्रीं श्रीं लक्ष्मीभयो नमः॥
Om Hreem Shreem Lakshmibhayo Namah॥
Lakshmi Beej Mantra is considered as origin of all powers of Goddess Lakshmi. The Beej Mantra of Goddess Lakshmi is only श्रीं, which is combined with other words to form various Mantras.