Maa Brahmcharini is the second form of Maa Durga, in this form she did hard penance(Tapasya) to get Lord Shiva as her Husband.

Mantra: दधाना करपद्माभ्यामक्षमालाकमण्डलू। देवी प्रसीदतु मयि ब्रह्मचारिण्यनुत्तमा॥

Dadhanakara Padmabhyam akshamala kamandalam, Devi prasidathu mayi rahmacharinya nuththama.