Introduction to the Bija mantra

First, an introduction to bija mantras.

The Sanskrit word "bija" means "seed".  Bija sounds are, therefore, simple
sounds [having no inherent meaning] which are used, either alone or in
conjunction with other bija sounds and mantras, to add power and draw in
various types of energy.  The simplest way to use these mantras is to focus on
their meanings and chant them over and over [called "japa"; commonly done
using a mala (type of prayer beads consisting of 108 beads plus one
guru/sumeru bead)].  They can also be used in combination with longer mantras
which are more specific in their focus.

"Bija Mantras are seed mantras having several syllables and are supposed to be
more powerful than other mantras.  To add power to a mantra, sometimes these
bijas are added, either at the beginning or at the end, or at both the
beginning and the end.  Bija Mantras may or may not convey sense, but their
meanings are the forms of the particular gods or goddesses whose bijas they
are"
Tools for Tantra p. 43, Harish Johari

Various Bija Mantras

Aum - the most basic of all mantras, sound of creation.  Aum has no specific
use as its energy is that of the absolute and can, therefore, be said for any
purpose.

Eim - Saraswati, intelligence, wisdom, spiritual growth and purity,
creativity, etc.

Srim [Shreem] - Laxmi, abundance, wealth, prosperity, plenty

Dum - Durga, protection, strength, power

Gam - Ganesh, removal of obstacles, unification

Krim - Kali, force, power, action, destruction [of ignorance, ego, etc]

Kshraum - Narasimha, protection, destruction of negativity


One-Line Mantras
Here are examples of how these bija sounds can be used to create simple
mantras to chant either for specific purposes or to pay homage to a deity. 
The basic outline of these mantras is simple:  Aum - the absolute, bija,
[deity name] the 'yai' suffix puts the name in the dative case, namaha - "I
bow".

Aum Eim Saraswatyai Namaha - "I bow to Saraswati"; this mantra is often said
by students [of whom Saraswati is the patron] in order to acquire her
blessings and attain good grades.  It is also said as an offering to Saraswati
[usually at least one mala is said].

Aum Srim MahaLaxmyai Namaha - "Maha" means "great"; similar to the mantra
above, but said for things such as financial gain.

[another common mantra of Laxmi is "Aum Shrim Hrim Klim MahaLaxmyai Namah"]

Aum Dum Durgayai Namaha

Aum Gam Ganapatyai Namaha

Aum Krim Kalikayai Namaha

Aum Kshraum Narasimhayai Namaha


Chakra Bijas
These bijas are intoned to aid in opening, clearing, and balancing the chakras.

Muladhara - Lam

Swadhistana - Vam

Manipura - Ram

Anahata - Yam

Vishuddha - Ham

Ajna - Aum

Sahasrara - Most sources state that Sahasrara Chakra has no mantra.


Here is an example of how bijas can be combined to create one large mantra.

"Eim Hrim Srim Klim Sauh Klim Hrim Eim Blum Strim
Nilatari Saraswati
Dram Drim Klim Blum Sauh
Eim Hrim Srim Klim Sauh Hrim Swaha

This 'freight train' mantra is a succession of seed sounds and is therefore
essentially untranslatable.  Faithful repletion of this mantra will, over
time, transform the sayer into a person of great spiritual knowledge."
Shakti Mantras: Tapping into the Great Goddess Energy Within, p. 46, Thomas
Ashley-Farrand